Maintaining molecular sieve catalytic activity under water vapor conditions

ABSTRACT

The invention is directed to methods for protecting metalloaluminophosphate molecular sieves, particularly silicoaluminophosphate (SAPO) molecular sieves, from loss of catalytic activity due to contact with a gas containing water. The methods of the invention provide procedures that enable activated sieve to contact water vapor, within a certain range of time, temperature, and water partial pressure conditions, before the sieve becomes substantially deactivated.

FIELD OF THE INVENTION

This invention relates to methods of maintaining or protecting thecatalytic activity of a molecular sieve. In particular, this inventionrelates to methods of maintaining or protecting the catalytic activityof a metalloaluminophosphate molecular sieve under water vapor orsteaming conditions.

BACKGROUND OF THE INVENTION

Molecular sieves are generally derived from alumina silicate materialsand contain a pore system, which is a network of uniform pores and emptycavities. These pores and cavities catch molecules that have a sizeequal to or less than the size of the pores and cavities, and repelmolecules of a larger size.

The pores and cavities of molecular sieves are formed as a result ofadding template materials during the molecular sieve manufacturingprocess. During the formation of the molecular sieves themselves, alattice type chemical structure is formed from the alumina silicate typematerials. This lattice type structure essentially wraps around thetemplate material, with the template material acting as a means offorming the pore structure within the molecular sieve. The resultingmolecular sieve may be combined with other components for the benefit ofadjusting various properties of the molecular sieve or to form largerparticles.

To make the molecular sieve suitable for use, the template must beremoved so that the pores and cavities are open to catch molecules,either for the purpose of adsorbing the molecules from the environmentor to react the molecules to form a desired product. The reaction occurswhen the molecules come into contact with catalytic sites located withinthe pore system, particularly within one or more of the empty cavitiesor cages as sometimes called.

The template is conventionally removed from the molecular sieve bycalcining or burning out the template. An elution process can also beused to remove the template, although calcination is preferred. Once thetemplate is removed, the molecular sieve is considered to be activatedor ready for use. The activated molecular sieve has its pore system,including the empty cavities or cages open to the immediate environment,and ready for use.

Activated metalloaluminophosphate molecular sieves that have catalyticsites within their microporous structure, e.g., silicoaluminophosphate(SAPO) molecular sieves, have been found to be sensitive to moisture. Ingeneral, significant exposure of the activated molecular sieves tomoisture has been found to deactivate the catalytic activity of themolecular sieves. Unfortunately, methods of protecting activatedmetalloaluminophosphate molecular sieves against the harmful effects ofmoisture are limited.

U.S. Pat. No. 6,316,683 B1 (Janssen et al.) discloses a method ofprotecting catalytic activity of a SAPO molecular sieve by shielding theinternal active sites of the molecular sieve from contact with moisture.The template itself can serve as the shield, or an anhydrous blanket canserve as a shield for an activated sieve that does not include template.It is desirable to shield the active sites, because activated SAPOmolecular sieves will exhibit a loss of catalytic activity when exposedto moisture.

U.S. Pat. No. 4,764,269 (Edwards et al.) discloses a method ofprotecting SAPO-37 catalyst from deactivating as a result of contactwith moisture. The catalyst is maintained under storage conditions suchthat the organic template component of the molecular sieve is retainedin the SAPO-37 molecular sieve, until such time as the catalyst isplaced into a catalytic cracking unit. When the catalyst is exposed tothe FCC reaction conditions, wherein the reactor is operated at 400° to600° C. and the regenerator operated at about 600° to 850° C., theorganic template is removed from the molecular sieve pore structure, andthe catalyst becomes activated for the cracking of hydrocarbons.According to this procedure, there is little if any contact withmoisture.

Mees et al., “Improvement of the Hydrothermal Stability of SAPO-34,”Chem. Commun., 2003, (1), 44-45, first published as an advance articleon the web Nov. 22, 2002, discloses a method of protecting SAPO-34molecular sieve, based on a reversible reaction of NH₃ with acid sitesof the sieve. The method transforms a H⁺-SAPO-34 into an NH₄ ⁺-SAPO-34in reversible way. The NH₄ ⁺-SAPO-34 is said to be able to withstandsevere steaming for an extended period of time without loss ofstructural integrity and acidity.

As new large scale, commercial production facilities, which usemetalloaluminophosphate molecular sieves in the production process,continue to be implemented, protecting the activatedmetalloaluminophosphate molecular sieves from loss of catalytic activityas a result of contact with moisture continues to become an even greaterchallenge. It is a particular challenge in catalytic reaction systemswhere large scale operation will entail contacting the activatedmolecular sieve with water vapor, particularly at times of start-up,shut-down, or as a result of a system interruption or failure. Duringsuch times, it may be necessary to use steam to keep the reaction systemheated or at appropriate catalyst bed densities. Even at highertemperature ranges, contact of the activated sieve with water vapor canresult in sieve that has little to no catalytic activity, which meansthat the sieve would then be of essentially no commercial value.

SUMMARY OF THE INVENTION

In one aspect, this invention provides methods that assist in theprotection of metalloaluminophosphate molecular sieves against loss ofcatalytic activity. These methods are particularly effective undercertain conditions where activated molecular sieve is contacted withwater vapor or steam. In one embodiment, the activatedmetalloaluminophosphate molecular sieve is protected against loss ofcatalytic activity by contacting the molecular sieve with a gascontaining water at a temperature above water critical temperature. Inanother embodiment, the molecular sieve is protected against loss ofcatalytic activity by contacting the molecular sieve with a gascontaining water at a temperature below water critical temperature tomaintain a desired or predetermined catalytic activity index.

In one embodiment, the invention provides a method of protectingactivated metalloaluminophosphate molecular sieve from loss of catalyticactivity, which comprises contacting the activatedmetalloaluminophosphate molecular sieve with a gas containing water at atemperature and water partial pressure effective to maintain themolecular sieve at a desirable or predetermined catalytic activity index(CAI), e.g., a CAI capable of converting hydrocarbon feed to desirableproduct. The catalytic activity index is represented by the formula:CAI=exp(f(T)*f(PP _(water))^(n)*alpha*t)

-   -   wherein    -   t=time of contact of catalyst with water (hours)    -   T=temperature at contact (° C.)    -   PP_(water)=Partial Pressure of water in contact gas (psia)    -   alpha=−0.071    -   n=3.5    -   f(T)=exp(ea(1/(T+273)−1/(T_(o)+273)))    -   ea=−5500° K    -   T_(o)=200° C.    -   f(PP_(water))=(26.2*PP_(water)/P_(sat)+1.14)*0.175, for        T≧180° C. (453° K)    -   f(PP_(water))=((26.2+0.272*(180−T))*PP_(water)/P_(sat)+1.14)*0.175,        for 180° C. (453° K)>T>150° C. (433° K)    -   Psat=Saturation pressure of water at T (psia).

In one embodiment, a desirable or predetermined catalytic activity indexis a CAI of at least 0.7. Preferably, the desirable or predeterminedcatalytic activity index is a CAI of at least 0.8, more preferably acatalytic activity index of at least 0.9.

This invention particularly pertains to exposing activated molecularsieve to gas (i.e., exposing to a gas) environment that contains water.In one embodiment, the gas contacting the sieve (i.e., the gasenvironment of the sieve) has a relative water pressure of at least0.0001. In another embodiment, the gas containing water has a relativewater pressure of at least 0.001; in another, a relative water pressureof at least 0.01, and in yet another a relative water pressure of atleast 0.1.

In one embodiment of the invention, the activated molecular sieve iscontacted with a gas containing water, or maintained in an environmenthaving water, which is at a temperature equal to or greater than watercritical temperature to minimize water adsorption. In anotherembodiment, gas containing water can be contacted with activatedcatalyst below water critical temperature; for example, at a temperatureof from about 150° C. to about 300° C., at a temperature of from about160° C. to about 280° C., and at a temperature of from about 180° C. toabout 260° C.

In another embodiment, the activated molecular sieve is contacted withgas containing water or exposed to the environment containing water fora time that does not significantly impact the catalytic activity index.Generally, the activated molecular sieve is contacted with the gas fornot greater than about 500 hours, preferably not greater than about 250hours, more preferably not greater than about 100 hours. In otherembodiments, the gas is contacted with the activated molecular sievefrom about 0.01 hour to about 50 hours, or from about 0.1 hour to about50 hours, and more preferably not greater than about 24 hours or about12 hours or about 6 hours.

In yet another embodiment of the invention, the activatedmetalloaluminophosphate molecular sieve is contacted with a gas thatcontains water, but for a time, and at a temperature, that does notsignificantly affect ethylene or propylene selectivity. Preferably, theactivated metalloaluminophosphate molecular sieve is contacted with thegas for a time effective to maintain an ethylene or propyleneselectivity of at least about 25 wt %, more preferably at least about 30wt %, and most preferably at least about 35 wt %.

In one embodiment of the invention, the activated molecular sieve iscontacted with gas containing water or exposed to the environment so asto minimize water adsorption. Desirably, the water partial pressure ofthe contacting gas or the environment is controlled so that activatedmolecular sieve adsorbs little to no water. Preferably, the activatedmolecular sieve exposed to the gas containing water or the environmenthas a water content of not greater than about 1.25 wt %, based on dryweight of the activated molecular sieve. More preferably, the activatedmolecular sieve has a water content of not greater than about 1.0 wt %,still more preferably not greater than about 0.8 wt %, and mostpreferably not greater than about 0.5 wt %, based on total weight of theactivated molecular sieve.

The molecular sieves used herein are preferably metalloaluminophosphatemolecular sieves that have a molecular framework that include [AlO₄] and[PO₄] tetrahedral units, such as metal containing aluminophosphates(AlPO). In one embodiment, the metalloaluminophosphate molecular sievesinclude [AlO₄], [PO₄] and [SiO₄] tetrahedral units, such assilicoaluminophosphates (SAPO). Preferred metalloaluminophosphatemolecular sieves include one or a combination of SAPO-5, SAPO-8,SAPO-11, SAPO-16, SAPO-17, SAPO-18, SAPO-20, SAPO-31, SAPO-34, SAPO-35,SAPO-36, SAPO-37, SAPO-40, SAPO-41, SAPO-42, SAPO-44, SAPO-47, SAPO-56,AlPO-5, AlPO-11, AlPO-18, AlPO-31, AlPO-34, AlPO-36, AlPO-37, AlPO-46,and metal containing molecular sieves thereof.

In one embodiment of the invention, the metalloaluminophosphatemolecular sieves contain silicon and aluminum. Desirably, themetalloaluminophosphate molecular sieves contain Si and Al at a Si/Alratio of not greater than about 0.5, preferably not greater than about0.3, more preferably not greater than about 0.2, still more preferablynot greater than about 0.15, and most preferably not greater than about0.1. In another embodiment, the metalloaluminophosphate molecular sievescontain Si and Al at a ratio of at least about 0.005, more preferably atleast about 0.01, and most preferably at least about 0.02.

In a preferred embodiment, catalytic activity is representative ofcatalytic activity in reaction processes selected from the groupconsisting of catalytic cracking, hydrocracking, dewaxing, olefinforming reactions, aromatics forming reactions, paraffin isomerization,olefin isomerization, paraffin hydroisomerization, olefinhydroisomerization, olefin oligomerization, olefin polymerization,reforming, alkylation, and disproportionation of aromatics. Olefinforming reactions are preferred.

In a further embodiment, the invention is directed to a method ofprotecting catalytic activity of an activated metalloaluminophosphatemolecular sieve in olefin forming reactions due to contact with watervapor. The method comprises contacting the activatedmetalloaluminophosphate molecular sieve with a gas for a time effectiveto maintain the activated metalloaluminophosphate molecular sieve at adesirable or predetermined catalytic activity index (e.g., at acatalytic activity index of at least 0.7, etc.). Preferably, theactivated molecular sieve is also maintained at an ethylene or propyleneselectivity of at least 25 wt %. The gas contains water up to saturationconditions, e.g., is at a relative water pressure of from 0.0001 to 1.The catalytic activity index can be maintained under conditions wherethe gas contacts the activated molecular sieve at a temperature lessthan water critical temperature.

The invention in another aspect is directed to a process for formingolefin product from oxygenate feed. The process comprises contacting anactivated metalloaluminophosphate molecular sieve with a gas containingwater at conditions effective to maintain the activated sieve at adesirable or predetermined catalytic activity index (e.g., a catalyticactivity index of at least 0.7, etc.), preferably at an ethylene orpropylene selectivity of at least 25 wt %. The water-contacted sieve canbe contacted with an oxygenate feed to form an olefin product, whereinthe olefin product contains greater than 50 weight percent olefin, basedon total weight of hydrocarbon produced. The olefin in the olefinproduct can be converted into a variety of products, includingpolyolefins.

In another embodiment, the invention includes a process for convertingoxygenate to an olefin product, which includes a step of loading anactivated metalloaluminophosphate molecular sieve into a reactionsystem. The activated metalloaluminophosphate molecular sieve loadedinto the reaction system is contacted with a gas containing water atconditions effective to maintain the activated sieve at an ethylene orpropylene selectivity effective to convert an oxygenate feed to anolefin product, with the olefin product containing greater than 50weight percent olefin, based on total weight of hydrocarbon produced.The water-contacted sieve can then be contacted with an oxygenate feedto form the olefin product, and the olefin product can then be convertto other products such as polyolefins.

The invention further provides a method of activatingmetalloaluminophosphate molecular sieve. In the method, ametalloaluminophosphate molecular sieve containing template is provided.The metalloaluminophosphate molecular sieve is calcined in a calcinationunit to remove the template. Once calcined, gas is swept through thecalcination unit to cool the calcined metalloaluminophosphate molecularsieve, while maintaining the calcined metalloaluminophosphate molecularsieve at a desirable catalytic activity index of at least. The sweep gascontains a measurable amount of water, such as a gas having a relativewater pressure of at least 0.0001. The gas is desirably sufficientlycool to cool the calcined molecular sieve, such as at a temperature lessthan water critical temperature.

The invention also includes a method of starting-up an olefin formingreaction system. The method comprises sweeping gas through the reactionsystem to heat up the system, with the reaction system containingactivated metalloaluminophosphate molecular sieve. Gas is swept throughthe reaction system while maintaining and the activatedmetalloaluminophosphate molecular sieve at a desirable or predeterminedcatalytic activity index. The activated metalloaluminophosphatemolecular sieve can be contacted in the heated up system with anoxygenate to form an olefin product.

In another aspect, the invention is directed to a method ofshutting-down an olefin forming reaction system. The method includes astep of contacting an activated metalloaluminophosphate molecular sievein a reaction system with an oxygenate to form an olefin product.Contact of the activated metalloaluminophosphate molecular sieve withthe oxygenate is stopped and gas is swept through the reaction system tocool down the system. While the gas is swept through the reactionsystem, the activated metalloaluminophosphate molecular sieve ismaintained at a desirable or predetermined catalytic activity index. Thesystem is preferably maintained above water critical temperature, butcan be at a temperature less than water critical temperature.

Also provided by the invention is a method of protecting catalyticactivity of an activated metalloaluminophosphate molecular sieve inolefin forming reactions due to contact with water vapor. The methodcomprises contacting the activated metalloaluminophosphate molecularsieve with a gas containing water to effectively maintain the activatedmetalloaluminophosphate molecular sieve at a desirable or predeterminedcatalytic activity index, and the activated metalloaluminophosphatemolecular sieve contains Si and Al at a Si/Al ratio of not greater than0.5. In a preferred embodiment, the activated metalloaluminophosphatemolecular sieve contains Si and Al at a Si/Al ratio of not greater than0.3, more preferably not greater than 0.2, still more preferably notgreater than 0.15, and most preferably not greater than 0.1.

BRIEF DESCRIPTION OF THE DRAWING

One embodiment of invention is shown in the attached FIGURE, which showsthe effect of water on an activated molecular sieve.

DETAILED DESCRIPTION OF THE INVENTION I. General Description ofInvention

This invention is directed to methods for protectingmetalloaluminophosphate molecular sieves, particularlysilicoaluminophosphate (SAPO) molecular sieves, from loss of catalyticactivity due to contact with water. The methods of this invention areparticularly effective, because they provide procedures that enableactivated sieve to contact water vapor, within a certain range of time,temperature, and water partial pressure conditions, before the sievebecomes substantially deactivated.

The inventors have now found that adsorption of water molecules by anactivated metalloaluminophosphate molecular sieve can be controlled byadjusting the conditions of the partial pressure of water in the gas orenvironment contacting the molecular sieve, the temperature of contact,and the time of contact. Controlling water adsorption controls the rateof deactivation, since generally the more water adsorbed results in agreater rate of deactivation. If activated molecular sieve does notadsorb any water, then there will be little to no deactivation as aresult of having activated molecular sieve exposed to the environment.

According to this invention, deactivation of the molecular sieve isdetermined by a catalytic activity index (CAI). The CAI provides ameasure of catalyst deactivation as a result of catalyst exposuretemperature, relative water pressure, and water contact time working inconcert to deactivate the catalyst. Thus, for example, although a lowrelative water pressure generally causes less catalyst deactivation,higher relative water pressures may be mitigated by limiting the contacttime or controlling the catalyst exposure temperature. The CAI formulaof this invention fully describes allowable combinations of time,temperature and relative water pressure to limit catalyst deactivationto specified values.

The catalytic activity index of this invention is defined as the actualcatalytic activity at time of measurement divided by the maximumcatalytic activity (before any deactivation occurs). In this regard, theCAI would be 0 for a completely deactivated catalyst, and I for acatalyst having maximum catalytic activity.

The catalytic activity index (CAI) is calculated according to thefollowing equation.CAI=exp(f(T)*f(PP _(water))^(n)*alpha*t)

-   -   wherein    -   t=time of contact of catalyst with water (hours)    -   T=temperature at contact (° C.)    -   PP_(water)=Partial Pressure of water in contact gas (psia)    -   alpha=−0.071    -   n=3.5    -   f(T)=exp(ea(1/(T+273)−1/(T_(o)+273)))    -   ea=−5500° K    -   T_(o)=200° C.    -   f(PP_(water))=(26.2*PP_(water)/P_(sat)+1.14)*0.175, for        T≧180° C. (453° K)    -   f(PP_(water))=((26.2+0.272*(180−T))*PP_(water)/P_(sat)+1.14)*0.175,        for 180° C. (453° K)>T>150° C. (433° K)    -   Psat=Saturation pressure of water at T (psia).

In a preferred embodiment, catalytic activity is representative ofcatalytic activity in reaction processes selected from the groupconsisting of catalytic cracking, hydrocracking, dewaxing, olefinforming reactions, aromatics forming reactions, paraffin isomerization,olefin isomerization, paraffin hydroisomerization, olefinhydroisomerization, olefin oligomerization, olefin polymerization,reforming, alkylation, and disproportionation of aromatics. In the caseof olefin forming reactions, catalyst lifetime is a desirablemeasurement of catalytic activity. In this invention, a catalyst isconsidered completely inactive when methanol conversion on a water-freebasis is less than 10%.

In one embodiment of the invention, activated metalloaluminophosphatemolecular sieve is contacted with a gas that contains water, but for atime, and at a temperature, that does not significantly deactivate thecatalyst. Preferably, the activated molecular sieve is contacted withthe gas for a time effective to maintain a catalytic activity index(CAI) of at least 0.7. Much below this level, the catalyst issubstantially ineffective, and selectivity to desired end products canalso be significantly affected. More preferably, the activated molecularsieve is contacted with the gas for a time effective to maintain acatalytic activity index of at least 0.8, and most preferably acatalytic activity index of at least 0.9.

In another embodiment of the invention, the activatedmetalloaluminophosphate molecular sieve is activated SAPO molecularsieve, and the activated SAPO is contacted with a gas that containswater, but for a time, and at a temperature, that does not significantlyaffect ethylene or propylene selectivity. Ethylene or propyleneselectivity is the actual selectivity of the catalyst to form ethyleneor propylene in the product. Preferably, the activated SAPO molecularsieve is contacted with the gas for a time effective to maintain anethylene or propylene selectivity of at least about 25 wt %, morepreferably at least about 30 wt %, and most preferably at least about 35wt %.

Adsorption of water by activated molecular sieve occurs in situationswhere gas contacting the activated molecular sieve or the environment inwhich the activated sieve is in, contains at least a measurable amountof water, i.e., conditions in which the environment or the contactinggas is not considered completely dry. The amount of water in the gas canbe effectively determined according to the relative water pressure ofthe gas. Relative water pressure (P_(r)) in this invention is defined asactual partial pressure of the water (PP_(water)) divided by saturatedwater pressure (P_(sat)) at a given temperature below the criticaltemperature of water (374° C.). The relative water pressure is a measureof the wetness of the environment in which the activated molecular sieveis contacted with the gas. For example, a P_(r)=1 means 100% watersaturation, and a P_(r)=0 means that the gas or environment iscompletely dry.

In this invention relative water pressure can range from very low, i.e.,low humidity conditions, to a value of 1, saturated water conditions.For example, at 205° C., if the catalyst is purged with room air (at 23°C. and at 71% relative humidity), this air contains water at a patialpressure of 0.29 psia (71/100*0.41=0.29, where 0.41 psia is thesaturation water pressure at 23° C.). When this air is heated up to 205°C., the relative water pressure becomes 0.29/250=0.00116, where 250 psiais the saturation water pressure at 205° C. The relative humidity of thegas at 205° C. is 0.00116*100=0.116%. This example illustrates that onecan use high humidity room air to do the purging at elevated temperatureto provide an environment having a low relative water pressure.

In general, the higher the water pressure, the greater the tendency ofthe contact with the gas to deactivate the catalyst, given constantcatalyst exposure temperature and time of gas contact. Nevertheless, byincreasing temperature or lowering time of contact, increased waterpressure can be tolerated. In one embodiment of the invention, the gascontacting the sieve (i.e., the gas environment of the sieve) has arelative water pressure of at least 0.0001. In another embodiment, thegas containing water has a relative water pressure of at least 0.001; inanother, a relative water pressure of at least 0.01, and in yet anothera relative water pressure of at least 0.1.

The gas that contains the water and contacts the activated molecularsieve can be any gas that can contain water. Preferably the gascontaining the water is selected from the group consisting of air,nitrogen, helium, flue gas, CO₂, and any combination thereof. Air ismost preferred, as air is generally used in various unit operations suchas starting-up and shutting-down the reaction system, including thereactor and regenerator sections of the reaction system.

According to this invention, activated molecular sieve is highlysusceptible to water damage at temperatures less than water criticaltemperature. As generally understood, critical temperature is thetemperature above which a gas cannot be liquefied, regardless of thepressure.

In one embodiment of the invention, the activated molecular sieve iscontacted with a gas containing water, or maintained in an environmenthaving water, which is at a temperature equal to or greater than watercritical temperature to minimize water adsorption. There is no upperlimit to the temperature, except to a practical extent of unitoperations. For example, a practical temperature limit is generally onenot greater than about 1,000° C., preferably not greater than about 900°C., more preferably not greater than about 800° C. In anotherembodiment, gas containing water can be contacted with activatedcatalyst below water critical temperature, but at a time and relativewater pressure to maintain the desired catalytic activity index. In aparticular embodiment, the gas contacts the activated molecular sieve ata temperature of from about 150° C. to about 300° C. In anotherembodiment, the gas contacts the activated molecular sieve at atemperature of from about 160° C. to about 280° C., and in yet anotherembodiment at a temperature of from about 180° C. to about 260° C.

The higher the relative water pressure of the contacting gas, or thelower the temperature of the gas, the greater the effect of loss oncatalytic activity. Generally, the activated molecular sieve iscontacted with the gas for not greater than about 500 hours. Preferably,the activated molecular sieve is contacted with the gas for not greaterthan about 250 hours, more preferably not greater than about 100 hours.In other embodiments, the gas is contacted with the activated molecularsieve from about 0.01 hour to about 50 hours, or from about 0.1 hour toabout 50 hours, and more preferably not greater than about 24 hours orabout 12 hours or about 6 hours.

II. Making and Storing Activated Sieve and Formulated Catalyst

This invention is effective in protecting molecular sieves, such asmetalloaluminophosphate molecular sieves, which contain active catalyticsites that are catalytically sensitive to water molecules. Suchmolecular sieves can be catalytically deactivated as a result of havingthe active catalytic sites come into significant contact with watermolecules.

Even slight amounts of water entrained in the internal pore system ofvarious metalloaluminophosphate molecular sieves can have an undesirableeffect on catalytic activity. Desirably, no water should be retained bythe activated molecular sieves. Preferably, the activated molecularsieves have a water content of not greater than about 1.25 wt %, basedon dry weight of the activated molecular sieve. More preferably, theactivated molecular sieve has a water content of not greater than about1.0 wt %, still more preferably not greater than about 0.8 wt %, andmost preferably not greater than about 0.5 wt %, based on total weightof the activated molecular sieve. The amount of water entrained in theactivated molecular sieve can be effectively reduced using conventionaldrying techniques. Preferably, the activated molecular sieve is dried byheating to a temperature of greater than water critical temperature.

Deactivation can occur upon activation of the sieves in an unformulatedor formulated state. According to this invention, however, deactivationcan be controlled to acceptable limits by controlling one or morevariables of time of contact with the water molecules, catalysttemperature at contact, and relative water pressure of the contactenvironment or any gas contacting the activated sieve.

Contact of activated molecular sieve with water vapor can occur in avariety of process systems and throughout various locations within suchprocess systems. Such processes include the manufacture of the activatedmolecular sieves or formulated molecular sieve catalysts that have beenactivated; handling, shipment, and storage of the activated sieves orformulated catalysts; and use of the sieves or catalysts in reactorsystems including the reactor and regenerator units in the reactorsystems and in catalyst loading, transfer and discharging equipment.

A. Types of Molecular Sieves

The molecular sieves used herein are preferably metalloaluminophosphatemolecular sieves that have a molecular framework that include [AlO4] and[PO4] tetrahedral units, such as metal containing aluminophosphates(AlPO). In one embodiment, the metalloaluminophosphate molecular sievesinclude [AlO4], [PO4] and [SiO4] tetrahedral units, such assilicoaluminophosphates (SAPO). These silicon, aluminum, and phosphorusbased molecular sieves and metal-containing derivatives thereof havebeen described in detail in numerous publications including for example,U.S. Pat. No. 4,567,029 (MeAPO where Me is Mg, Mn, Zn, or Co), U.S. Pat.No. 4,440,871 (SAPO), European Patent Application EP-A-0 159 624 (ELAPSOwhere El is As, Be, B, Cr, Co, Ga, Ge, Fe, Li, Mg, Mn, Ti or Zn), U.S.Pat. No. 4,554,143 (FeAPO), U.S. Pat. Nos. 4,822,478, 4,683,217,4,744,885 (FeAPSO), EP-A-0 158 975 and U.S. Pat. No. 4,935,216 (ZnAPSO,EP-A-0 161 489 (CoAPSO), EP-A-0 158 976 (ELAPO, where EL is Co, Fe, Mg,Mn, Ti or Zn), U.S. Pat. No. 4,310,440 (AIPO4), EP-A-0 158 350(SENAPSO), U.S. Pat. No. 4,973,460 (LiAPSO), U.S. Pat. No. 4,789,535(LiAPO), U.S. Pat. No. 4,992,250 (GeAPSO), U.S. Pat. No. 4,888,167(GeAPO), U.S. Pat. No. 5,057,295 (BAPSO), U.S. Pat. No. 4,738,837(CrAPSO), U.S. Pat. Nos. 4,759,919, and 4,851,106 (CrAPO), U.S. Pat.Nos. 4,758,419, 4,882,038, 5,434,326 and 5,478,787 (MgAPSO), U.S. Pat.No. 4,554,143 (FeAPO), U.S. Pat. No. 4,894,213 (AsAPSO), U.S. Pat. No.4,913,888 (AsAPO), U.S. Pat. Nos. 4,686,092, 4,846,956 and 4,793,833(MnAPSO), U.S. Pat. Nos. 5,345,011 and 6,156,931 (MnAPO), U.S. Pat. No.4,737,353 (BeAPSO), U.S. Pat. No. 4,940,570 (BeAPO), U.S. Pat. Nos.4,801,309, 4,684,617 and 4,880,520 (TiAPSO), U.S. Pat. Nos. 4,500,651,4,551,236 and 4,605,492 (TiAPO), U.S. Pat. Nos. 4,824,554, 4,744,970(CoAPSO), U.S. Pat. No. 4,735,806 (GaAPSO) EP-A-0 293 937 (QAPSO, whereQ is framework oxide unit [QO2]), as well as U.S. Pat. Nos. 4,567,029,4,686,093, 4,781,814, 4,793,984, 4,801,364, 4,853,197, 4,917,876,4,952,384, 4,956,164, 4,956,165, 4,973,785, 5,241,093, 5,493,066 and5,675,050, all of which are herein fully incorporated by reference.

Other molecular sieves include those described in R. Szostak, Handbookof Molecular Sieves, Van Nostrand Reinhold, New York, N.Y. (1992), whichis herein fully incorporated by reference.

The more preferred molecular sieves are SAPO molecular sieves, andmetal-substituted SAPO molecular sieves. Suitable metal substituents arealkali metals of Group IA of the Periodic Table of Elements, an alkalineearth metals of Group IIA of the Periodic Table of Elements, a rareearth metals of Group IIIB, including the Lanthanides: lanthanum,cerium, praseodymium, neodymium, samarium, europium, gadolinium,terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium;and scandium or yttrium of the Periodic Table of Elements, transitionmetals of Groups IVB, VB, VIIB, VIIB, VIIIB, and IB of the PeriodicTable of Elements and mixtures of any of these metal species. In oneembodiment, the metal is selected from the group consisting of Co, Cr,Cu, Fe, Ga, Ge, Mg, Mn, Ni, Sn, Ti, Zn and Zr, and mixtures thereof. Themetal atoms may be inserted into the framework of a molecular sievethrough a tetrahedral unit, such as [MeO2], and carry a net chargedepending on the valence state of the metal substituent. For example, inone embodiment, when the metal substituent has a valence state of +2,+3, +4, +5, or +6, the net charge of the tetrahedral unit is between −2and +2.

In one embodiment, the metalloaluminophosphate molecular sieve isrepresented, on an anhydrous basis, by the formula:mR:(M_(x)Al_(y)P_(z))O₂

wherein R represents at least one templating agent, preferably anorganic templating agent; m is the number of moles of R per mole of(M_(x)Al_(y)P_(z))O₂ and m has a value from 0 to 1, preferably 0 to 0.5,and most preferably from 0 to 0.3; x, y, and z represent the molefraction of Al, P and M as tetrahedral oxides, where M is a metalselected from the group consisting of Group IA, IIA, IB, IIIB, IVB, VB,VIIB, VIIB, VIIIB and Lanthanide's of the Periodic Table of Elements.Preferably M is one or more metals selected from the group consisting ofSi, Co, Cr, Cu, Fe, Ga, Ge, Mg, Mn, Ni, Sn, Ti, Zn and Zr. In anembodiment, m is greater than or equal to 0.2, and x, y and z aregreater than or equal to 0.01. In another embodiment, m is greater than0.1 to about 1, x is greater than 0 to about 0.25, y is in the range offrom 0.4 to 0.5, and z is in the range of from 0.25 to 0.5, morepreferably m is from 0.15 to 0.7, x is from 0.01 to 0.2, y is from 0.4to 0.5, and z is from 0.3 to 0.5.

In one embodiment of the invention, the metalloaluminophosphatemolecular sieves contain silicon and aluminum. In general, lower Si/Alratios lead to lower deactivation rates and higher ACIs for a given setof conditions. However, higher Si/Al ratios can be used under theappropriate conditions of temperature, water partial pressure and timeof contact with water. Desirably, the metalloaluminophosphate molecularsieves of this invention contain Si and Al, at a Si/Al ratio of notgreater than about 0.5, preferably not greater than about 0.3, morepreferably not greater than about 0.2, still more preferably not greaterthan about 0.15, and most preferably not greater than about 0.1. Inanother embodiment, the Si/Al ratio is sufficiently high to allow forincreased catalytic activity of the molecular sieve. Preferably, themetalloaluminophosphate molecular sieves contain Si and Al at a ratio ofat least about 0.005, more preferably at least about 0.01, and mostpreferably at least about 0.02.

Non-limiting examples of SAPO and AlPO molecular sieves useful hereininclude one or a combination of SAPO-5, SAPO-8, SAPO-11, SAPO-16,SAPO-17, SAPO-18, SAPO-20, SAPO-31, SAPO-34, SAPO-35, SAPO-36, SAPO-37,SAPO-40, SAPO-41, SAPO-42, SAPO-44, SAPO-47, SAPO-56, AlPO-5, AlPO-11,AlPO-18, AlPO-31, AlPO-34, AlPO-36, AlPO-37, AlPO-46, and metalcontaining molecular sieves thereof. Of these, particularly usefulmolecular sieves are one or a combination of SAPO-18, SAPO-34, SAPO-35,SAPO-44, SAPO-56, AlPO-18, AlPO-34 and metal containing derivativesthereof, such as one or a combination of SAPO-18, SAPO-34, AlPO-34,AlPO-18, and metal containing derivatives thereof, and especially one ora combination of SAPO-34, AlPO-18, and metal containing derivativesthereof.

In an embodiment, the molecular sieve is an intergrowth material havingtwo or more distinct crystalline phases within one molecular sievecomposition. In particular, intergrowth molecular sieves are describedin U.S. Patent Application Publication No. 2002-0165089 andInternational Publication No. WO 98/15496, published Apr. 16, 1998, bothof which are herein fully incorporated by reference. For example,SAPO-18, AlPO-18 and RUW-18 have an AEI framework-type, and SAPO-34 hasa CHA framework-type. Thus, the molecular sieve used herein may compriseat least one intergrowth phase of AEI and CHA framework-types,especially where the ratio of CHA framework-type to AEI framework-type,as determined by the DIFFaX method disclosed in U.S. Patent ApplicationPublication No. 2002-0165089, is greater than 1:1.

Generally, molecular sieves (i.e., molecular sieve crystals) aresynthesized by the hydrothermal crystallization of one or more of asource of aluminum, a source of phosphorus, a source of silicon, waterand a templating agent, such as a nitrogen containing organic compound.Typically, a combination of sources of silicon and aluminum, or silicon,aluminum and phosphorus, water and one or more templating agents, isplaced in a sealed pressure vessel. The vessel is optionally lined withan inert plastic such as polytetrafluoroethylene, and heated under acrystallization pressure and temperature, until a crystalline materialis formed, which can then be recovered by filtration, centrifugationand/or decanting.

Non-limiting examples of silicon sources include silicates, fumedsilica, for example, Aerosil-200 available from Degussa Inc., New York,N.Y., and CAB-O-SIL M-5, organosilicon compounds such astetraalkylorthosilicates, for example, tetramethylorthosilicate (TMOS)and tetraethylorthosilicate (TEOS), colloidal silicas or aqueoussuspensions thereof, for example Ludox-HS-40 sol available from E.I. duPont de Nemours, Wilmington, Del., silicic acid or any combinationthereof.

Non-limiting examples of aluminum sources include aluminum alkoxides,for example aluminum isopropoxide, aluminum phosphate, aluminumhydroxide, sodium aluminate, pseudo-boehmite, gibbsite and aluminumtrichloride, or any combination thereof. A convenient source of aluminumis pseudo-boehmite, particularly when producing a silicoaluminophosphatemolecular sieve.

Non-limiting examples of phosphorus sources, which may also includealuminum-containing phosphorus compositions, include phosphoric acid,organic phosphates such as triethyl phosphate, and crystalline oramorphous aluminophosphates such as AlPO₄, phosphorus salts, orcombinations thereof. A convenient source of phosphorus is phosphoricacid, particularly when producing a silicoaluminophosphate.

In general, templating agents or templates include compounds thatcontain elements of Group 15 of the Periodic Table of Elements,particularly nitrogen, phosphorus, arsenic and antimony. Typicaltemplates also contain at least one alkyl or aryl group, such as analkyl or aryl group having from 1 to 10 carbon atoms, for example from 1to 8 carbon atoms. Preferred templates are nitrogen-containingcompounds, such as amines, quaternary ammonium compounds andcombinations thereof. Suitable quaternary ammonium compounds arerepresented by the general formula R₄N⁺, where each R is hydrogen or ahydrocarbyl or substituted hydrocarbyl group, preferably an alkyl groupor an aryl group having from 1 to 10 carbon atoms.

Non-limiting examples of templates include tetraalkyl ammonium compoundsincluding salts thereof, such as tetramethyl ammonium compounds,tetraethyl ammonium compounds, tetrapropyl ammonium compounds, andtetrabutylammonium compounds, cyclohexylamine, morpholine,di-n-propylamine (DPA), tripropylamine, triethylamine (TEA),triethanolamine, piperidine, cyclohexylamine, 2-methylpyridine,N,N-dimethylbenzylamine, N,N-diethylethanolamine, dicyclohexylamine,N,N-dimethylethanolamine, choline, N,N′-dimethylpiperazine,1,4-diazabicyclo(2,2,2)octane, N′,N′,N,N-tetramethyl-(1,6)hexanediamine,N-methyldiethanolamine, N-methyl-ethanolamine, N-methyl piperidine,3-methyl-piperidine, N-methylcyclohexylamine, 3-methylpyridine,4-methyl-pyridine, quinuclidine, N,N′-dimethyl-1,4-diazabicyclo(2,2,2)octane ion; di-n-butylamine, neopentylamine, di-n-pentylamine,isopropylamine, t-butyl-amine, ethylenediamine, pyrrolidine, and2-imidazolidone. Preferred templates are selected from the groupconsisting of tetraethyl ammonium salts, cyclopentylamine, aminomethylcyclohexane, piperidine, triethylamine, cyclohexylamine, tri-ethylhydroxyethylamine, morpholine, dipropylamine (DPA), pyridine,isopropylamine, heated degraded forms thereof, and combinations thereof.

The pH of the synthesis mixture containing at a minimum a silicon,aluminum, optionally a phosphorus composition, and a templating agent,is generally in the range of from 2 to 10, such as from 4 to 9, forexample from 5 to 8.

Generally, the synthesis mixture described above is sealed in a vesseland heated, preferably under autogenous pressure, to a temperature inthe range of from about 80° C. to about 250° C., such as from about 100°C. to about 250° C., for example from about 125° C. to about 225° C.,such as from about 150° C. to about 180° C.

In one embodiment, the synthesis of molecular sieve crystallineparticles is aided by seeds from another or the same framework typemolecular sieve.

The time required to form the crystalline particles is usually dependenton the temperature and can vary from immediately up to several weeks.Typically, the crystallization time is from about 30 minutes to around 2weeks, such as from about 45 minutes to about 240 hours, for examplefrom about 1 hour to about 120 hours. The hydrothermal crystallizationmay be carried out with or without agitation or stirring.

One method for crystallization involves subjecting an aqueous reactionmixture containing an excess amount of a templating agent tocrystallization under hydrothermal conditions, establishing anequilibrium between molecular sieve formation and dissolution, and then,removing some of the excess templating agent and/or organic base toinhibit dissolution of the molecular sieve. See, for example, U.S. Pat.No. 5,296,208, which is herein fully incorporated by reference.

Other methods for synthesizing molecular sieves or modifying molecularsieves are described in U.S. Pat. No. 5,879,655 (controlling the ratioof the templating agent to phosphorus), U.S. Pat. No. 6,005,155 (use ofa modifier without a salt), U.S. Pat. No. 5,475,182 (acid extraction),U.S. Pat. No. 5,962,762 (treatment with transition metal), U.S. Pat.Nos. 5,925,586 and 6,153,552 (phosphorus modified), U.S. Pat. No.5,925,800 (monolith supported), U.S. Pat. No. 5,932,512 (fluorinetreated), U.S. Pat. No. 6,046,373 (electromagnetic wave treated ormodified), U.S. Pat. No. 6,051,746 (polynuclear aromatic modifier), U.S.Pat. No. 6,225,254 (heating template), PCT WO 01/36329 published May 25,2001 (surfactant synthesis), PCT WO 01/25151 published Apr. 12, 2001(staged acid addition), PCT WO 01/60746 published Aug. 23, 2001 (siliconoil), U.S. patent application Ser. No. 09/929,949 filed Aug. 15, 2001(cooling molecular sieve), U.S. patent application Ser. No. 09/615,526filed Jul. 13, 2000 (metal impregnation including copper), U.S. patentapplication Ser. No. 09/672,469 filed Sep. 28, 2000 (conductivemicrofilter), and U.S. patent application Ser. No. 09/754,812 filed Jan.4, 2001 (freeze drying the molecular sieve), which are all herein fullyincorporated by reference.

Once the crystalline molecular sieve product is formed, usually in aslurry state, it may be recovered by any standard technique well knownin the art, for example, by centrifugation or filtration. The recoveredcrystalline particle product, normally termed the “wet filter cake”, maythen be washed, such as with water, and then dried, such as in air,before being formulated into a catalyst composition. Alternatively, thewet filter cake may be formulated into a catalyst composition directly,that is without any drying, or after only partial drying.

B. Making Formulated Molecular Sieve Catalyst

1. Components of Formulated Molecular Sieve Catalyst

Molecular sieve catalyst, which contains molecular sieve crystalproduct, and typically binder and matrix materials, is also referred toas a formulated catalyst. It is made by mixing together molecular sievecrystals (which includes template) and a liquid, optionally with matrixmaterial and/or binder, to form a slurry. The slurry is then dried(i.e., liquid is removed), without completely removing the template fromthe molecular sieve. Since this dried molecular sieve catalystincludes-template, it has not been activated, and is considered apreformed catalyst. The catalyst in this form is resistant to catalyticloss by contact with moisture or water. However, the preformed catalystmust be activated before use, and this invention provides appropriatemethods to protect the activated catalyst from significant deactivation.

The liquid used to form the slurry can be any liquid conventionally usedin formulating molecular sieve catalysts. Non-limiting examples ofsuitable liquids include water, alcohol, ketones, aldehydes, esters, ora combination thereof. Water is a preferred liquid.

Matrix materials are optionally included in the slurry used to make theformulated molecular sieve catalyst of this invention. Such materialsare typically effective as thermal sinks assisting in shielding heatfrom the catalyst composition, for example, during regeneration. Theycan further act to densify the catalyst composition, increase catalyststrength such as crush strength and attrition resistance, and to controlthe rate of conversion in a particular process. Non-limiting examples ofmatrix materials include one or more of: rare earth metals, metal oxidesincluding titania, zirconia, magnesia, thoria, beryllia, quartz, silicaor sols, and mixtures thereof; for example, silica-magnesia,silica-zirconia, silica-titania, silica-alumina andsilica-alumina-thoria.

In one embodiment, matrix materials are natural clays, such as thosefrom the families of montmorillonite and kaolin. These natural claysinclude kaolins known as, for example, Dixie, McNamee, Georgia andFlorida clays. Non-limiting examples of other matrix materials include:halloysite, kaolinite, dickite, nacrite, or anauxite. Optionally, thematrix material, preferably any of the clays, are calcined, acidtreated, and/or chemical treated before being used as a slurrycomponent. Under the optional calcination treatment, the matrix materialwill still be considered virgin material as long as the material has notbeen previously used in a catalyst formulation.

In a particular embodiment, the matrix material is a clay or a clay-typecomposition, preferably a clay or clay-type composition having a lowiron or titania content, and most preferably the matrix material iskaolin. Kaolin has been found to form a pumpable, high solid contentslurry; it has a low fresh surface area, and it packs together easilydue to its platelet structure.

Preferably, the matrix material, particularly clay, and preferablykaolin, has an average particle size of from about 0.05 μm to about 0.75μm; more preferably from about 0.1 μm to about 0.6 μm. It is alsodesirable that the matrix material have a d₉₀ particle size distributionof less than about 1.5 μm, preferably less than about 1 μm.

Binders are also optionally included in the slurry used to make theformulated molecular sieve catalysts of this invention. Such materialsact like glue, binding together the molecular sieve crystals and othermaterials, to form a formulated catalyst composition. Non-limitingexamples of binders include various types of inorganic oxide sols suchas hydrated aluminas, silicas, and/or other inorganic oxide sols. In oneembodiment of the invention, the binder is an alumina-containing sol,preferably aluminium chlorohydrate. Upon calcining, the inorganic oxidesol, is converted into an inorganic oxide matrix component, which isparticularly effective in forming a hardened molecular sieve catalystcomposition. For example, an alumina sol will convert to an aluminiumoxide matrix following heat treatment.

Aluminium chlorohydrate, a hydroxylated aluminium based sol containing achloride counter ion, also known as aluminium chlorohydrol, has thegeneral formulaAl_(m)O_(n)(OH)_(o)Cl_(p) .x(H₂O)wherein m is to 20, n is 1 to 8, o is 5 to 40, p is 2 to 15, and x is 0to 30. In one embodiment, the binder is Al₁₃O₄(OH)₂₄Cl₇.12(H₂O) as isdescribed in G. M. Wolterman, et al., Stud Surf Sci. and Catal., 76,pages 105-144, Elsevier, Amsterdam, 1993, which is herein incorporatedby reference. In another embodiment, one or more binders are present incombination with one or more other non-limiting examples of aluminamaterials such as aluminium oxyhydroxide, γ-alumina, boehmite andtransitional aluminas such as α-alumina, β-alumina, γ-alumina,δ-alumina, ε-alumina, κ-alumina, and ρ-alumina, aluminium trihydroxide,such as gibbsite, bayerite, nordstrandite, doyelite, and mixturesthereof.

In another embodiment, the binders are alumina sols, predominantlycomprising aluminium oxide, optionally including silicon. In yet anotherembodiment, the binders are peptised alumina made by treating aluminahydrates such as pseudobohemite, with an acid, preferably a non-halogenacid, to prepare sols or aluminium ion solutions. Non-limiting examplesof commercially available colloidal alumina sols include Nalco 8676available from Nalco Chemical Co., Naperville, Ill., and Nyacolavailable from the Nyacol Nano Technology Inc., Boston, Mass.

If binder is not used in making the molecular sieve catalyst, thecatalyst is considered a binderless catalyst. If binder is used, theamount of binder used to prepare the molecular sieve catalyst rangesfrom about 2% by weight to about 30% by weight, based on the totalweight of the binder, the molecular sieve, and optionally includedmatrix material, excluding the liquid (i.e., after drying). Preferablythe amount of binder used to prepare the molecular sieve catalyst rangesfrom about 5% by weight to about 20% by weight, more preferably fromabout 7% by weight to about 15% by weight, based on the total weight ofthe binder, the molecular sieve, and optionally included matrixmaterial, excluding the liquid (i.e., after drying).

2. Making a Slurry with Molecular Sieve Crystals

The molecular sieve crystals are mixed with liquid, and the optionalmatrix material and/or binder, using conventional techniques to form aslurry. The components can be mixed in any order, and the mixture isthoroughly stirred to form the slurry. The more thorough the stirring,the better the consistency of the slurry.

The mixing of the slurry is preferably sufficient to break anyaggregates or large particles into smaller, more uniform particles. Ingeneral, the more vigorous the mixing, the smaller the catalystparticles formed in the slurry. Mixing using high-shear mixers ispreferred. In general, high-shear mixers are capable of rotating atspeeds of at least about 3,000 rpm laboratory scale equivalent.

Solids particle size of the slurry can be indirectly determined bymeasuring the viscosity of the slurry. In general, the higher theviscosity, the smaller the solids particle size in the slurry. Theviscosity of the slurry should not be too high, so that mixing is noteffective in breaking apart large particles, or too low, so that dryingwill not produce acceptable particle formation.

In one embodiment, the slurry has a viscosity of from about 100 cP (0.1Pa/sec) to about 9,500 cP (9.5 Pa/sec), as measured using a BrookfieldLV-DVE viscometer with a No. 3 spindle at 10 rpm. Preferably, the slurryhas a viscosity of from about 200 cP (0.2 Pa/sec) to about 8,500 cP (8.5Pa/sec), and more preferably from about 350 cP (0.375 Pa/sec) to about8,000 cP (8 Pa/sec), as measured using a Brookfield LV-DVE viscometerwith a No. 3 spindle at 10 rpm.

In another embodiment, the slurry has a solids content of from about 10wt % to about 75 wt %, based on total weight of the slurry. Preferablythe slurry has a solids content of from about 15 wt % to about 70 wt %,more preferably from about 20 wt % to about 65 wt %, based on the totalweight of the slurry. The solids content can be measured using anyconventional means. However, a CEM MAS 700 microwave muffle furnace isparticularly preferred to give results consistent with the valuesrecited herein.

In one embodiment, the slurry used to make the formulated molecularsieve catalyst contains binder and matrix material at a weight ratio offrom 0:1 to 1:1. Preferably, the slurry used to make the molecular sievecatalyst contains binder and matrix material at a weight ratio of from1:15 to 1:2, more preferably 1:10 to 1:2, and most preferably 1:6 to1:1. In case where binders are not used, the molecular sieve componentitself acts as a binder.

3. Making a Preformed Catalyst

Water is removed from the slurry containing the molecular sieve crystalsto form a preformed molecular sieve catalyst. Preferably, the slurry isfed to a forming unit that produces the preformed molecular sievecatalyst composition. The forming unit may be any conventional unit,such as a spray dryer, pelletizer, extruder, etc. In a preferredembodiment, the forming unit is spray dryer, which removes water fromthe slurry by a heating or drying process. Preferably, the forming unitis maintained at a temperature sufficient to remove a majority of theliquid from the slurry.

When a spray dryer is used as the forming (or drying) unit, typically,the slurry of the molecular sieve particles, and optional matrixmaterial and/or binder, is fed to the spray drying unit along with adrying gas. The drying gas contacts the slurry and acts to remove waterto form the preformed molecular sieve catalyst. Conventional dryingconditions can be used. Such conditions include an average inlettemperature ranging from about 150° C. to about 550° C., and an averageoutlet temperature ranging from about 100° C. to about 250° C.

During spray drying, the slurry is passed through a nozzle distributingthe slurry into small droplets, resembling an aerosol spray, into adrying chamber where atomization occurs. Atomization is achieved byforcing the slurry through a single nozzle or multiple nozzles with apressure drop in the range of from about 100 psia to about 1,000 psia(about 690 kPaa to about 6,895 kPaa). In another embodiment, the slurryis fed through a single nozzle or multiple nozzles along with anatomization or contacting fluid such as air, steam, flue gas, or anyother suitable gas.

In yet another embodiment, the slurry that is used to make the preformedcatalyst is directed to the perimeter of a spinning wheel thatdistributes the slurry into small droplets. The size of the droplets iscontrolled by one or more factors including slurry viscosity, surfacetension, flow rate, pressure, and temperature of the slurry; the shapeand dimension of the nozzle(s); or the spinning rate of the wheel. Thesedroplets are then dried in a co-current or counter-current flow of airpassing through a spray drier to form a preformed molecular sievecatalyst composition. An example of a conventional spray drying processis described in U.S. Pat. No. 4,946,814, which is incorporated herein byreference.

C. Activating the Sieve or Formulated Catalyst

The molecular sieve material is activated by removing the template fromthe preformed molecular sieve catalyst composition so as to expose theactive catalytic sites to the environment. The template can be removedby any conventional technique, including for example by elution methodsor by heating. The molecular sieve crystals themselves can be activatedfor immediate catalytic use or for storing or transporting prior to use.However, it is preferred that the molecular sieves be formulated into apreformed catalyst, then activated, since the sieves are typically mostuseful as a formulated product. The formulated product generallyprovides the most effective particle size and hardness for commercialscale equipment.

In one embodiment of the invention, the molecular sieve material isactivated by removing the template by heat. In a preferred embodiment,the heat is sufficient to remove water that is formed as a result of thecombustion of the template. Preferably, the molecular sieve material isheated at a temperature greater than the critical temperature of water.At this temperature, water formed during the combustion process will notcondense or be retained by the molecular sieve. Preferably, the templateis removed by contacting with steam at a temperature greater than thecritical temperature of water. More preferably, following removal of thetemplate, any water entrained in the catalyst is also removed,preferably by appropriate heating using a dry gas. Preferably, the drygas has a relative water pressure of less than 0.0001.

Heating to remove template and activate the molecular sieve is generallyreferred to in this invention as calcination. Conventional calcinationdevices can be used. Such devices include rotary calciners, fluid bedcalciners, batch ovens, and the like. Calcination time is typicallydependent on the degree of hardening of the molecular sieve catalystcomposition and the temperature.

Conventional calcination temperatures are effective to remove templatematerials and to activate the molecular sieve catalyst of thisinvention. Such temperatures are generally in the range from about 400°C. to about 1,000° C., preferably from about 500° C. to about 800° C.,and most preferably from about 550° C. to about 700° C.

D. Storage of Activated Sieve or Formulated Catalyst

Following heat activation by calcining for example, the activatedmolecular sieve is cooled, since it will generally be at a temperaturethat is too high for immediately handling or loading into a container.In a preferred embodiment, the activated molecular sieve or formulatedmolecular sieve catalyst is cooled and stored so that there is not asubstantial reduction in catalytic activity index.

In one embodiment, molecular sieve containing template or a preformedcatalyst is calcined in a calcination unit to activate the molecularsieve. Following calcination, the activated molecular sieve or catalystcontaining the activated molecular sieve (collectively activatedmolecular sieve) is cooled, and placed in a container for transport orstorage. This activation and subsequent cooling can be carried out inseparate units or in the same unit, particularly in separate regions ofthe same unit.

Once the temperature of the catalyst falls below water criticaltemperature, catalyst deactivation begins to occur as water moleculeswill generally be present as a result of the combustion process. Gas canbe swept through the calcination unit to aid in cooling, and the sweepgas can also contain water vapor. Although the presence of watermolecules can deactivate active catalytic sites, the presence of somewater is tolerated according to this invention, since catalysttemperature and time of contact with water vapor can be controlled tominimize catalyst deactivation.

Examples of sweep gas (the gas contacting the activated molecular sieve)include air, nitrogen, helium, flue gas, CO₂, and any combinationthereof. The gas that contacts the activated molecular sieve contains atleast a measurable amount of water, typically having a relative waterpressure of at least 0.0001. By increasing temperature or lowering timeof contact, increased water pressure can be tolerated. In oneembodiment, the gas containing water has a relative water pressure of atleast 0.001; in another, a relative water pressure of at least 0.01, andin yet another a relative water pressure of at least 0.1.

At temperatures where water adsorption by the activated catalyst canoccur (e.g., below water critical temperature, such as not greater than300° C., 280° C. or 260° C.), the activated molecular sieve is contactedwith the sweep gas (i.e., the gas is swept through the calcination unit)to cool the molecular sieve, and for a time effective to maintain acatalytic activity index of at least 0.7, preferably at least 0.8, andmore preferably at least 0.9. The activated molecular sieve is desirablycontacted with the sweep gas (i.e., the gas is swept through thecalcination unit) for not greater than 500 hours, preferably not greaterthan 250 hours, more preferably not greater than 100 hours. In otherembodiments, the sweep gas is contacted with the activated molecularsieve in the calcination unit from 0.01 hour to 50 hours, or from 0.1hour to 50 hours, and more preferably not greater than 24 hours or 12hours or about 6 hours.

In yet another embodiment of the invention, the container provides ananhydrous environment for the activated sieve. Such an environment canbe provided by covering the activated sieve loaded into a container witha gas or liquid blanket under anhydrous conditions. As provided herein,the anhydrous gas or liquid blanket will have no more than a limitedamount of water. The anhydrous gas blanket can be provided under vacuumconditions or under atmospheric or greater pressure conditions, and willdesirably have not greater than about 1.2 volume percent water,preferably not greater than about 0.2 volume percent water, and morepreferably not greater than about 0.02 volume percent water. Theanhydrous liquid blanket will desirably have not greater than about 200ppm water, preferably not greater than about 100 ppm water, and morepreferably not greater than about 50 ppm water. The anhydrousenvironment can be applied during storage, transport or loading of theactivated material.

The anhydrous gas blanket is a gas under standard temperature andpressure conditions and does not react to any significant degree withthe molecular sieve structure. The gas is preferably selected from thegroup consisting of nitrogen, helium, CO, CO₂, H₂, argon, O₂, lightalkanes (especially C₁-C₄ alkanes, particularly methane and ethane),cyclo-alkanes and mixtures thereof, e.g. air. Air is a preferred gas.The gas blanket can be maintained at any pressure, including undervacuum or at pressures above standard, even if the gas becomes liquid atpressures above standard, as long as the conditions remain anhydrous.

The anhydrous liquid blanket is a liquid under standard temperature andpressure conditions, and does not react to any significant degree withthe molecular sieve structure. The liquid is preferably selected fromthe group consisting of alkanes, cyclo-alkanes, C₆-C₃₀ aromatics,alcohols, particularly C₄+ branched alcohols.

III. Reaction System Operations in the Presence of Water

The methods of this invention can be used in any reaction systems thatuse metalloaluminophosphate molecular sieves containing active catalyticsites that are catalytically sensitive to water molecules. Such reactionsystems include catalytic cracking, hydrocracking, dewaxing, olefinforming reactions, aromatics forming reactions, paraffin isomerization,olefin isomerization, paraffin hydroisomerization, olefinhydroisomerization, olefin oligomerization, olefin polymerization,reforming, alkylation, and disproportionation of aromatics.

In operation, the various reaction systems are generally operated attemperatures above the water critical temperature. In certain unitoperations, e.g., unit start-up, unit shut-down, unit interruptions,etc., temperatures may drop to below water critical temperature. Ifwater vapor is present when temperatures drop to below the watercritical temperature, catalyst deactivation occurs. It is, therefore,important that the reaction systems be operated to control one or morevariables of time of contact with the water molecules, temperature dropbelow the critical water temperature, and relative water pressure in thereaction system.

In one embodiment, the reaction system is heated to start-up thereaction system by sweeping a gas containing water through at least apart of the system. Examples of sweep gas (the gas contacting theactivated molecular sieve) include air, nitrogen, helium, flue gas, CO₂,and any combination thereof. The gas that contacts the activatedmolecular sieve contains at least a measurable amount of water,typically having a relative water pressure of at least 0.0001. Byincreasing temperature or lowering time of contact, increased waterpressure can be tolerated. Increased water pressure is also desired tothe extent that water generally has a higher heat capacity than dry gas,so the water will have a greater effect on heating up the reactionsystem. In one embodiment, the gas containing water has a relative waterpressure of at least 0.001; in another, a relative water pressure of atleast 0.01, and in yet another a relative water pressure of at least0.1.

The gas that is used to sweep the reaction system at start-up isdesirably above water critical temperature. However, at initial start-upprocedures the environment will likely be cooler than the gas itself. Insuch an environment, it is desirable to maintain a temperature of atleast about 150° C. where there is contact with water molecules in thesweep gas and the activated catalyst. At system temperatures below watercritical temperature, e.g., not greater than 300° C., 280° C. or 260°C., the activated molecular sieve is contacted with the sweep gas (i.e.,the gas is swept through the system) for a time effective to maintain acatalytic activity index of at least 0.7, preferably at least 0.8, andmore preferably at least 0.9. The activated molecular sieve is loadedinto the system either before or during the start-up procedure, and isdesirably contacted with the sweep gas (i.e., the gas is swept throughthe system) for not greater than 500 hours, preferably not greater than250 hours, more preferably not greater than 100 hours. In otherembodiments, the sweep gas is contacted with the activated molecularsieve from 0.01 hour to 50 hours, or from 0.1 hour to 50 hours, and morepreferably not greater than 24 hours or 12 hours or about 6 hours.

It is desirable to heat up the reaction system as quickly as possible soas to minimize any possible damage to the catalyst in the system as aresult of the catalyst coming into contact with moisture below thecritical water temperature. Once, the system is above critical watertemperature, and is at a desirable start-up temperature, circulation ofthe sweep gas is stopped and feed introduced. The feed is then contactedwith the activated catalyst in the system to form desirable product. Ina preferred embodiment, the feed is an oxygenate and the product is anolefin-containing product.

In one embodiment, the reaction system is cooled to shut-down thereaction. At shut-down gas is also swept through the system to cool thesystem down. Water molecules will generally be present in the gas duringthis unit operation. Examples of sweep gas (the gas contacting theactivated molecular sieve) include air, nitrogen, helium, flue gas, CO₂,and any combination thereof. The gas that contacts the activatedmolecular sieve contains at least a measurable amount of water,typically having a relative water pressure of at least 0.0001. Byincreasing temperature or lowering time of contact, increased waterpressure can be tolerated. Increased water pressure is also desired tothe extent that water generally has a higher heat capacity than dry gas,so the water will have a greater effect on cooling down the reactionsystem. In one embodiment, the gas containing water has a relative waterpressure of at least 0.001; in another, a relative water pressure of atleast 0.01, and in yet another a relative water pressure of at least0.1.

The gas that is used to sweep the reaction system at shut-down willeventually fall below water critical temperature. It is desirable tomaintain a shut-down temperature of at least about 150° C. for as longas reasonable where there is contact with water molecules in the sweepgas and the activated catalyst. At temperatures below water criticaltemperature, e.g., not greater than 300° C., 280° C. or 260° C., theactivated molecular sieve is contacted with the sweep gas (i.e., the gasis swept through the system) for a time effective to maintain acatalytic activity index of at least 0.7, preferably at least 0.8, andmore preferably at least 0.9. The activated molecular sieve is desirablycontacted with the sweep gas (i.e., the gas is swept through the sytem)for not greater than 500 hours, preferably not greater than 250 hours,more preferably not greater than 100 hours. In other embodiments, thesweep gas is contacted with the activated molecular sieve from 0.01 hourto 50 hours, or from 0.1 hour to 50 hours, and more preferably notgreater than 24 hours or 12 hours or about 6 hours.

During unit interruptions, it is desirable to maintain the reactionsystem at temperatures at least as high as water critical temperature.However, heat maintenance during unit interruptions can be difficult,leading to cool-down conditions. Under conditions where the temperaturedrops to lower than water critical temperature, the reaction system canbe effectively operated as in shut-down mode.

In one embodiment of the invention, the reaction system is an olefinforming reaction system in which feedstock is converted into one or moreolefin(s). Typically, the feedstock contains one or morealiphatic-containing compounds such that the aliphatic moiety containsfrom 1 to about 50 carbon atoms, such as from 1 to 20 carbon atoms, forexample from 1 to 10 carbon atoms, and particularly from 1 to 4 carbonatoms.

Non-limiting examples of aliphatic-containing compounds include alcoholssuch as methanol and ethanol, alkyl mercaptans such as methyl mercaptanand ethyl mercaptan, alkyl sulfides such as methyl sulfide, alkylaminessuch as methylamine, alkyl ethers such as dimethyl ether, diethyl etherand methylethyl ether, alkyl halides such as methyl chloride and ethylchloride, alkyl ketones such as dimethyl ketone, formaldehydes, andvarious acids such as acetic acid.

In a preferred embodiment of the process of the invention, the feedstockcontains one or more oxygenates, more specifically, one or more organiccompound(s) containing at least one oxygen atom. In the most preferredembodiment of the process of invention, the oxygenate in the feedstockis one or more alcohol(s), preferably aliphatic alcohol(s) where thealiphatic moiety of the alcohol(s) has from 1 to 20 carbon atoms,preferably from 1 to 10 carbon atoms, and most preferably from 1 to 4carbon atoms. The alcohols useful as feedstock in the process of theinvention include lower straight and branched chain aliphatic alcoholsand their unsaturated counterparts.

Non-limiting examples of oxygenates include methanol, ethanol,n-propanol, isopropanol, methyl ethyl ether, dimethyl ether, diethylether, di-isopropyl ether, formaldehyde, dimethyl carbonate, dimethylketone, acetic acid, and mixtures thereof.

In the most preferred embodiment, the feedstock is selected from one ormore of methanol, ethanol, dimethyl ether, diethyl ether or acombination thereof, more preferably methanol and dimethyl ether, andmost preferably methanol.

The various feedstocks discussed above, particularly a feedstockcontaining an oxygenate, more particularly a feedstock containing analcohol, is converted primarily into one or more olefin(s). Theolefin(s) produced from the feedstock typically have from 2 to 30 carbonatoms, preferably 2 to 8 carbon atoms, more preferably 2 to 6 carbonatoms, still more preferably 2 to 4 carbons atoms, and most preferablyare ethylene and/or propylene.

The catalyst composition of the invention is particularly useful in theprocess that is generally referred to as the gas-to-olefins (GTO)process or, alternatively, the methanol-to-olefins (MTO) process. Inthis process, an oxygenated feedstock, most preferably amethanol-containing feedstock, is converted in the presence of amolecular sieve catalyst composition into one or more olefin(s),preferably and predominantly, ethylene and/or propylene.

Using the catalyst composition of the invention for the conversion of afeedstock, preferably a feedstock containing one or more oxygenates, theamount of olefin(s) produced based on the total weight of hydrocarbonproduced is greater than 50 weight percent, typically greater than 60weight percent, such as greater than 70 weight percent, and preferablygreater than 75 weight percent. In one embodiment, the amount ofethylene and/or propylene produced based on the total weight ofhydrocarbon product produced is greater than 65 weight percent, such asgreater than 70 weight percent, for example greater than 75 weightpercent, and preferably greater than 78 weight percent. Typically, theamount ethylene produced in weight percent based on the total weight ofhydrocarbon product produced, is greater than 30 weight percent, such asgreater than 35 weight percent, for example greater than 40 weightpercent. In addition, the amount of propylene produced in weight percentbased on the total weight of hydrocarbon product produced is greaterthan 20 weight percent, such as greater than 25 weight percent, forexample greater than 30 weight percent, and preferably greater than 35weight percent.

In addition to the oxygenate component, such as methanol, the feedstockmay contains one or more diluent(s), which are generally non-reactive tothe feedstock or molecular sieve catalyst composition and are typicallyused to reduce the concentration of the feedstock. Non-limiting examplesof diluents include helium, argon, nitrogen, carbon monoxide, carbondioxide, water, essentially non-reactive paraffins (especially alkanessuch as methane, ethane, and propane), essentially non-reactive aromaticcompounds, and mixtures thereof. The most preferred diluents are waterand nitrogen, with water being particularly preferred.

The diluent, for example water, may be used either in a liquid or avapor form, or a combination thereof. The diluent may be either addeddirectly to the feedstock entering a reactor or added directly to thereactor, or added with the molecular sieve catalyst composition.

The present process can be conducted over a wide range of temperatures,such as in the range of from about 200° C. to about 1000° C., forexample from about 250° C. to about 800° C., including from about 250°C. to about 750° C., conveniently from about 300° C. to about 650° C.,typically from about 350° C. to about 600° C. and particularly fromabout 350° C. to about 550° C.

Similarly, the present process can be conducted over a wide range ofpressures including autogenous pressure. Typically the partial pressureof the feedstock exclusive of any diluent therein employed in theprocess is in the range of from about 0.1 kPaa to about 5 MPaa, such asfrom about 5 kPaa to about 1 MPaa, and conveniently from about 20 kPaato about 500 kPaa.

The weight hourly space velocity (WHSV), defined as the total weight offeedstock excluding any diluents per hour per weight of molecular sievein the catalyst composition, typically ranges from about 1 hr⁻¹ to about5000 hr⁻¹, such as from about 2 hr⁻¹ to about 3000 hr⁻¹, for examplefrom about 5 hr⁻¹ to about 1500 hr⁻¹, and conveniently from about 10hr⁻¹ to about 1000 hr⁻¹. In one embodiment, the WHSV is greater than 20hr⁻¹ and, where feedstock contains methanol and/or dimethyl ether, is inthe range of from about 20 hr⁻¹ to about 300 hr⁻¹.

Where the process is conducted in a fluidized bed, the superficial gasvelocity (SGV) of the feedstock including diluent and reaction productswithin the reactor system, and particularly within a riser reactor(s),is at least 0.1 meter per second (m/sec), such as greater than 0.5m/sec, such as greater than 1 m/sec, for example greater than 2 m/sec,conveniently greater than 3 m/sec, and typically greater than 4 m/sec.See for example U.S. patent application Ser. No. 09/708,753 filed Nov.8, 2000, which is herein incorporated by reference.

The process of the invention is conveniently conducted as a fixed bedprocess, or more typically as a fluidized bed process (including aturbulent bed process), such as a continuous fluidized bed process, andparticularly a continuous high velocity fluidized bed process.

The process can take place in a variety of catalytic reactors such ashybrid reactors that have a dense bed or fixed bed reaction zones and/orfast fluidized bed reaction zones coupled together, circulatingfluidized bed reactors, riser reactors, and the like. Suitableconventional reactor types are described in for example U.S. Pat. No.4,076,796, U.S. Pat. No. 6,287,522 (dual riser), and FluidizationEngineering, D. Kunii and O. Levenspiel, Robert E. Krieger PublishingCompany, New York, N.Y. 1977, which are all herein fully incorporated byreference.

The preferred reactor types are riser reactors generally described inRiser Reactor, Fluidization and Fluid-Particle Systems, pages 48 to 59,F. A. Zenz and D. F. Othmo, Reinhold Publishing Corporation, New York,1960, and U.S. Pat. No. 6,166,282 (fast-fluidized bed reactor), and U.S.patent application Ser. No. 09/564,613 filed May 4, 2000 (multiple riserreactor), which are all herein fully incorporated by reference.

In one practical embodiment, the process is conducted as a fluidized bedprocess or high velocity fluidized bed process utilizing a reactorsystem, a regeneration system and a recovery system.

In such a process the reactor system conveniently includes a fluid bedreactor system having a first reaction zone within one or more riserreactor(s) and a second reaction zone within at least one disengagingvessel, typically comprising one or more cyclones. In one embodiment,the one or more riser reactor(s) and disengaging vessel are containedwithin a single reactor vessel. Fresh feedstock, preferably containingone or more oxygenates, optionally with one or more diluent(s), is fedto the one or more riser reactor(s) into which a molecular sievecatalyst composition or coked version thereof is introduced. In oneembodiment, prior to being introduced to the riser reactor(s), themolecular sieve catalyst composition or coked version thereof iscontacted with a liquid, preferably water or methanol, and/or a gas, forexample, an inert gas such as nitrogen.

In an embodiment, the amount of fresh feedstock fed as a liquid and/or avapor to the reactor system is in the range of from 0.1 weight percentto about 85 weight percent, such as from about 1 weight percent to about75 weight percent, more typically from about 5 weight percent to about65 weight percent based on the total weight of the feedstock includingany diluent contained therein. The liquid and vapor feedstocks may bethe same composition, or may contain varying proportions of the same ordifferent feedstocks with the same or different diluents.

The feedstock entering the reactor system is preferably converted,partially or fully, in the first reactor zone into a gaseous effluentthat enters the disengaging vessel along with the coked catalystcomposition. In the preferred embodiment, cyclone(s) are provided withinthe disengaging vessel to separate the coked catalyst composition fromthe gaseous effluent containing one or more olefin(s) within thedisengaging vessel. Although cyclones are preferred, gravity effectswithin the disengaging vessel can also be used to separate the catalystcomposition from the gaseous effluent. Other methods for separating thecatalyst composition from the gaseous effluent include the use ofplates, caps, elbows, and the like.

In one embodiment, the disengaging vessel includes a stripping zone,typically in a lower portion of the disengaging vessel. In the strippingzone the coked catalyst composition is contacted with a gas, preferablyone or a combination of steam, methane, carbon dioxide, carbon monoxide,hydrogen, or an inert gas such as argon, preferably steam, to recoveradsorbed hydrocarbons from the coked catalyst composition that is thenintroduced to the regeneration system.

The coked catalyst composition is withdrawn from the disengaging vesseland introduced to the regeneration system. The regeneration systemcomprises a regenerator where the coked catalyst composition iscontacted with a regeneration medium, preferably a gas containingoxygen, under conventional regeneration conditions of temperature,pressure and residence time.

Non-limiting examples of suitable regeneration media include one or moreof oxygen, O₃, SO₃, N₂O, NO, NO₂, N₂O₅, air, air diluted with nitrogenor carbon dioxide, oxygen and water (U.S. Pat. No. 6,245,703), carbonmonoxide and/or hydrogen. Suitable regeneration conditions are thosecapable of burning coke from the coked catalyst composition, preferablyto a level less than 0.5 weight percent based on the total weight of thecoked molecular sieve catalyst composition entering the regenerationsystem. For example, the regeneration temperature may be in the range offrom about 200° C. to about 1500° C., such as from about 300° C. toabout 1000° C., for example from about 450° C. to about 750° C., andconveniently from about 550° C. to 700° C. The regeneration pressure maybe in the range of from about 15 psia (103 kpaa) to about 500 psia (3448kpaa), such as from about 20 psia (138 kPaa) to about 250 psia (1724kpaa), including from about 25 psia (172 kPaa) to about 150 psia (1034kpaa), and conveniently from about 30 psia (207 kPaa) to about 60 psia(414 kpaa).

The residence time of the catalyst composition in the regenerator may bein the range of from about one minute to several hours, such as fromabout one minute to 100 minutes, and the volume of oxygen in theregeneration gas may be in the range of from about 0.01 mole percent toabout 5 mole percent based on the total volume of the gas.

The burning of coke in the regeneration step is an exothermic reaction,and in an embodiment, the temperature within the regeneration system iscontrolled by various techniques in the art including feeding a cooledgas to the regenerator vessel, operated either in a batch, continuous,or semi-continuous mode, or a combination thereof. A preferred techniqueinvolves withdrawing the regenerated catalyst composition from theregeneration system and passing it through a catalyst cooler to form acooled regenerated catalyst composition. The catalyst cooler, in anembodiment, is a heat exchanger that is located either internal orexternal to the regeneration system. Other methods for operating aregeneration system are in disclosed U.S. Pat. No. 6,290,916(controlling moisture), which is herein fully incorporated by reference.

The regenerated catalyst composition withdrawn from the regenerationsystem, preferably from the catalyst cooler, is combined with a freshmolecular sieve catalyst composition and/or re-circulated molecularsieve catalyst composition and/or feedstock and/or fresh gas or liquids,and returned to the riser reactor(s). In one embodiment, the regeneratedcatalyst composition withdrawn from the regeneration system is returnedto the riser reactor(s) directly, preferably after passing through acatalyst cooler. A carrier, such as an inert gas, feedstock vapor, steamor the like, may be used, semi-continuously or continuously, tofacilitate the introduction of the regenerated catalyst composition tothe reactor system, preferably to the one or more riser reactor(s).

By controlling the flow of the regenerated catalyst composition orcooled regenerated catalyst composition from the regeneration system tothe reactor system, the optimum level of coke on the molecular sievecatalyst composition entering the reactor is maintained. There are manytechniques for controlling the flow of a catalyst composition describedin Michael Louge, Experimental Techniques, Circulating Fluidized Beds,Grace, Avidan and Knowlton, eds., Blackie, 1997 (336-337), which isherein incorporated by reference.

Coke levels on the catalyst composition are measured by withdrawing thecatalyst composition from the conversion process and determining itscarbon content. Typical levels of coke on the molecular sieve catalystcomposition, after regeneration, are in the range of from 0.01 weightpercent to about 15 weight percent, such as from about 0.1 weightpercent to about 10 weight percent, for example from about 0.2 weightpercent to about 5 weight percent, and conveniently from about 0.3weight percent to about 2 weight percent based on the weight of themolecular sieve.

The gaseous effluent is withdrawn from the disengaging system and ispassed through a recovery system. There are many well known recoverysystems, techniques and sequences that are useful in separatingolefin(s) and purifying olefin(s) from the gaseous effluent. Recoverysystems generally comprise one or more or a combination of variousseparation, fractionation and/or distillation towers, columns,splitters, or trains, reaction systems such as ethylbenzene manufacture(U.S. Pat. No. 5,476,978) and other derivative processes such asaldehydes, ketones and ester manufacture (U.S. Pat. No. 5,675,041), andother associated equipment, for example various condensers, heatexchangers, refrigeration systems or chill trains, compressors,knock-out drums or pots, pumps, and the like.

Non-limiting examples of these towers, columns, splitters or trains usedalone or in combination include one or more of a demethanizer,preferably a high temperature demethanizer, a dethanizer, adepropanizer, a wash tower often referred to as a caustic wash towerand/or quench tower, absorbers, adsorbers, membranes, ethylene (C2)splitter, propylene (C3) splitter and butene (C4) splitter.

Various recovery systems useful for recovering olefin(s), such asethylene, propylene and/or butene, are described in U.S. Pat. No.5,960,643 (secondary rich ethylene stream), U.S. Pat. Nos. 5,019,143,5,452,581 and 5,082,481 (membrane separations), U.S. Pat. No. 5,672,197(pressure dependent adsorbents), U.S. Pat. No. 6,069,288 (hydrogenremoval), U.S. Pat. No. 5,904,880 (recovered methanol to hydrogen andcarbon dioxide in one step), U.S. Pat. No. 5,927,063 (recovered methanolto gas turbine power plant), and U.S. Pat. No. 6,121,504 (direct productquench), U.S. Pat. No. 6,121,503 (high purity olefins withoutsuperfractionation), and U.S. Pat. No. 6,293,998 (pressure swingadsorption), which are all herein fully incorporated by reference.

Other recovery systems that include purification systems, for examplefor the purification of olefin(s), are described in Kirk-OthmerEncyclopedia of Chemical Technology, 4th Edition, Volume 9, John Wiley &Sons, 1996, pages 249-271 and 894-899, which is herein incorporated byreference. Purification systems are also described in for example, U.S.Pat. No. 6,271,428 (purification of a diolefin hydrocarbon stream), U.S.Pat. No. 6,293,999 (separating propylene from propane), and U.S. patentapplication Ser. No. 09/689,363 filed Oct. 20, 2000 (purge stream usinghydrating catalyst), which are herein incorporated by reference.

Generally accompanying most recovery systems is the production,generation or accumulation of additional products, by-products and/orcontaminants along with the preferred prime products. The preferredprime products, the light olefins, such as ethylene and propylene, aretypically purified for use in derivative manufacturing processes such aspolymerization processes. Therefore, in the most preferred embodiment ofthe recovery system, the recovery system also includes a purificationsystem. For example, the light olefin(s) produced particularly in a MTOprocess are passed through a purification system that removes low levelsof by-products or contaminants.

Non-limiting examples of contaminants and by-products include generallypolar compounds such as water, alcohols, carboxylic acids, ethers,carbon oxides, sulfur compounds such as hydrogen sulfide, carbonylsulfides and mercaptans, ammonia and other nitrogen compounds, arsine,phosphine and chlorides. Other contaminants or by-products includehydrogen and hydrocarbons such as acetylene, methyl acetylene,propadiene, butadiene and butyne.

Typically, in converting one or more oxygenates to olefin(s) having 2 or3 carbon atoms, a minor amount hydrocarbons, particularly olefin(s),having 4 or more carbon atoms is also produced. The amount of C₄+hydrocarbons is normally less than 20 weight percent, such as less than10 weight percent, for example less than 5 weight percent, andparticularly less than 2 weight percent, based on the total weight ofthe effluent gas withdrawn from the process, excluding water. Typically,therefore the recovery system may include one or more reaction systemsfor converting the C₄+ impurities to useful products.

Non-limiting examples of such reaction systems are described in U.S.Pat. No. 5,955,640 (converting a four carbon product into butene-1),U.S. Pat. No. 4,774,375 (isobutane and butene-2 oligomerized to analkylate gasoline), U.S. Pat. No. 6,049,017 (dimerization ofn-butylene), U.S. Pat. Nos. 4,287,369 and 5,763,678 (carbonylation orhydroformulation of higher olefins with carbon dioxide and hydrogenmaking carbonyl compounds), U.S. Pat. No. 4,542,252 (multistageadiabatic process), U.S. Pat. No. 5,634,354 (olefin-hydrogen recovery),and Cosyns, J. et al., Process for Upgrading C3, C4 and C5 OlefinicStreams, Pet. & Coal, Vol. 37, No. 4 (1995) (dimerizing or oligomerizingpropylene, butylene and pentylene), which are all fully hereinincorporated by reference.

The preferred light olefin(s) produced by any one of the processesdescribed above are high purity prime olefin(s) products that contain asingle carbon number olefin in an amount greater than 80 percent, suchas greater than 90 weight percent, such as greater than 95 weightpercent, for example at least about 99 weight percent, based on thetotal weight of the olefin.

In one practical embodiment, the process of the invention forms part ofan integrated process for producing light olefin(s) from a hydrocarbonfeedstock, preferably a gaseous hydrocarbon feedstock, particularlymethane and/or ethane. The first step in the process is passing thegaseous feedstock, preferably in combination with a water stream, to asyngas production zone to produce a synthesis gas (syngas) stream,typically comprising carbon dioxide, carbon monoxide and hydrogen.Syngas production is well known, and typical syngas temperatures are inthe range of from about 700° C. to about 1200° C. and syngas pressuresare in the range of from about 2 MPa to about 100 MPa. Synthesis gasstreams are produced from natural gas, petroleum liquids, andcarbonaceous materials such as coal, recycled plastic, municipal wasteor any other organic material. Preferably synthesis gas stream isproduced via steam reforming of natural gas.

The next step in the process involves contacting the synthesis gasstream generally with a heterogeneous catalyst, typically a copper basedcatalyst, to produce an oxygenate containing stream, often incombination with water. In one embodiment, the contacting step isconducted at temperature in the range of from about 150° C. to about450° C. and a pressure in the range of from about 5. MPa to about 10MPa.

This oxygenate containing stream, or crude methanol, typically containsthe alcohol product and various other components such as ethers,particularly dimethyl ether, ketones, aldehydes, dissolved gases such ashydrogen methane, carbon oxide and nitrogen, and fuel oil. The oxygenatecontaining stream, crude methanol, in the preferred embodiment is passedthrough a well known purification processes, distillation, separationand fractionation, resulting in a purified oxygenate containing stream,for example, commercial Grade A and AA methanol.

The oxygenate containing stream or purified oxygenate containing stream,optionally with one or more diluents, can then be used as a feedstock ina process to produce light olefin(s), such as ethylene and/or propylene.Non-limiting examples of this integrated process are described in EP-B-0933 345, which is herein fully incorporated by reference.

In another more fully integrated process, that optionally is combinedwith the integrated processes described above, the olefin(s) producedare directed to, in one embodiment, one or more polymerization processesfor producing various polyolefins. (See for example U.S. patentapplication Ser. No. 09/615,376 filed Jul. 13, 2000, which is hereinfully incorporated by reference.)

Polymerization processes include solution, gas phase, slurry phase and ahigh pressure processes, or a combination thereof. Particularlypreferred is a gas phase or a slurry phase polymerization of one or moreolefin(s) at least one of which is ethylene or propylene. Thesepolymerization processes utilize a polymerization catalyst that caninclude any one or a combination of the molecular sieve catalystsdiscussed above. However, the preferred polymerization catalysts are theZiegler-Natta, Phillips-type, metallocene, metallocene-type and advancedpolymerization catalysts, and mixtures thereof.

In a preferred embodiment, the integrated process comprises a processfor polymerizing one or more olefin(s) in the presence of apolymerization catalyst system in a polymerization reactor to produceone or more polymer products, wherein the one or more olefin(s) havebeen made by converting an alcohol, particularly methanol, using amolecular sieve catalyst composition as described above. The preferredpolymerization process is a gas phase polymerization process and atleast one of the olefins(s) is either ethylene or propylene, andpreferably the polymerization catalyst system is a supported metallocenecatalyst system. In this embodiment, the supported metallocene catalystsystem comprises a support, a metallocene or metallocene-type compoundand an activator, preferably the activator is a non-coordinating anionor alumoxane, or combination thereof, and most preferably the activatoris alumoxane.

The polymers produced by the polymerization processes described aboveinclude linear low density polyethylene, elastomers, plastomers, highdensity polyethylene, low density polyethylene, polypropylene andpolypropylene copolymers. The propylene based polymers produced by thepolymerization processes include atactic polypropylene, isotacticpolypropylene, syndiotactic polypropylene, and propylene random, blockor impact copolymers.

IV. EXAMPLES A. Example 1

An activated SAPO-34 molecular sieve catalyst was loaded into a taperedelement oscillating microbalance (TEOM, Series 1500 Pulse Mass Analyzerfrom Rupprecht and Patashnick), and calcined under air at 625° C. untilall the coke present on the catalyst was removed. Coke removal wasconsidered complete when the change of mass measured by the TEOMreactor, as a function of time, was approximately zero. The duration ofcalcination was approximately one hour. After calcination was complete,the reactor temperature was brought to a methanol to olefins (MTO)reaction condition of 425° C., and allowed to stabilize. Subsequently,methanol at a constant flow rate was introduced to the reactor, and theMTO reaction was allowed to proceed. The products of the reaction (i.e.,C₂-C₅ hydrocarbons) were measured at discrete intervals of time usinggas chromatography (GC). The mass gain of the catalyst (due to cokeformation on the catalyst) as a function of time was recorded by theTEOM analytical unit. The MTO reaction was allowed to proceed until thecatalyst had sufficiently deactivated due to coke deposition on thecatalyst. Deactivation due to coke was considered complete when methanolconversion on a water-free basis was less than 10%. This procedure wasperformed in order to determine the catalytic activity of a catalystthat has not been subjected to steam (i.e., maximum catalytic activity).

Once the catalytic activity of the undamaged catalyst (i.e., maximumcatalytic activity) was determined, the catalyst was calcined using thesame procedure as above. After calcination was complete, the TEOMreactor was brought to various temperatures and partial pressures ofsteam. The partial pressure of steam was controlled by eitherintroducing pure steam to the reactor and adjusting the total reactorpressure, or by diluting the steam with nitrogen to achieve a desiredpartial pressure at a constant total reactor pressure. Thistemperature/partial pressure condition was held for measured durationsof time, generally between 4 and 12 hours, depending on the time scaleof deactivation. After the steaming portion of the test was complete,nitrogen was flowed through the catalyst sample in order to remove muchof the adsorbed water on the catalyst. That is, nitrogen was flowedthrough the catalyst bed until the mass lost as a function of time wasapproximately zero. The molecular sieve was then heated to 425° C. andallowed to equilibrate. The MTO reaction was run following the sameprocedure outlined above. Once the reaction was complete and samplesanalyzed by GC, the results of the analysis of the steam treated samplewere compared to that of the undamaged sample. The catalyst was thencalcined and treated with steam using the procedure previously outlinedto further damage the catalyst.

This procedure was repeated to determine steam damage as a function oftime at a given temperature and partial pressure of steam. Manytemperature and partial pressure combinations were tested, starting withan undamaged sample, in order to calculate the effect of temperature andsteam partial pressure upon catalyst deactivation.

Once an acceptable matrix of experiments was completed (experimentsperformed at various temperature/steam partial pressure conditions),relative catalytic activity indices were determined and compared asfunctions of temperature, steam partial pressure and time of contactwith steam. The results are shown in the Figure.

In this Example, catalyst deactivation was taken to be the lessening ofthe catalyst lifetime relative to an undamaged catalyst. Catalystlifetime was taken to be the amount of time taken for a given catalystto achieve less than 10% conversion of methanol on a water free basis.Deactivation is therefore presented as a fraction, that fraction beingthe ratio of the lifetime of the damaged catalyst over the lifetimeundamaged catalyst.

Referring to the Figure, two different values for CAI are shown, 0.8,and 0.95. All the points on each plane shown have the same CAI value. Atany combination of time, temperature, and water partial pressure above aparticular plane, the CAI will be less than the listed value. Forexample, Point 1 of the Figure represents catalyst being exposed to gasat a water partial pressure of 30.8 psia at 170° C. for 1.5 hours. TheCAI at these conditions is 0.8. By decreasing water partial pressure to18.7 psia, and keeping temperature and time of contact constant, the CAIis increased to 0.95. See Point 2 of the Figure. Thus, the Figuredemonstrates the effects of water partial pressure, temperature andcontact time on catalytic activity of activated metalloaluminophosphatemolecular sieve catalyst.

B. Example 2

The data from Example 1 was used to calculate a formula for catalyticactivity index (CAI). The formula is as follows:CAI=exp(f(T)*f(PP _(water))^(n)*alpha*t)

-   -   wherein    -   t=time of contact of catalyst with water (hours)    -   T=temperature at contact (° C.)    -   PP_(water)=Partial Pressure of water in contact gas (psia)    -   alpha=−0.071    -   n=3.5    -   f(T)=exp(ea(1/(T+273)−1/(T_(o)+273)))    -   ea=−5500° K    -   T_(o)=200° C.    -   f(PP_(water))=(26.2*PP_(water/P) _(sat)+1.14)*0.175, for        T>180° C. (453° K)    -   f(PP_(water))=((26.2+0.272*(180−T))*PP_(water)/P_(sat)+1.14)*0.175,        for 180° C. (453° K)>T>150° C. (433° K)    -   P_(sat)=Saturation pressure of water at T (psia)

Various water partial pressures, time of contact of catalyst withwater-containing gas, and contact temperatures were entered into theformula to calculate the corresponding catalytic activity indices. Theresults are shown in Table 1. TABLE 1 PP_(water) Time CAI at contacttemperature (T) (psia) (t, hours) 160° C. 200° C. 250° C. 15 6 0.82 0.960.98 12 0.67 0.92 0.95 25 6 0.37 0.88 0.95 12 0.14 0.77 0.9 40 6 0.010.64 0.88 12 1.50E−04 0.4 0.77

Table 1 shows the effects of water pressure, time of contact of catalystwith water vapor, and temperature of contact on CAI. The lower the CAI,the less active the catalyst. In general, the higher the temperature,the lower the water partial pressure, and the lower the time of contactwith water, the higher the CAI, which is highly desirable.

C. Example 3

Several catalysts (all metalloaluminophosphate molecular sieves) withvarious Si/Al ratio were tested under steaming conditions similar to theones described in Example 2. Table 2 below describes steaming conditionsand resulting CAI under the various Si/Al ratios. TABLE 2 PPwater T timeCatalyst Si/Al (psia) (° C.) (t, hours) CAI A 0.16 40 180 16 0.35 B 0.0740 180 16 0.8 C 0.02 40 225 16 1.0

The data in Table 2 demonstrates that lower Si/Al ratios lead to lowerdeactivation rates and higher CAIs for a given set of conditions.

Having now fully described this invention, it will be appreciated bythose skilled in the art that the invention can be performed within awide range of parameters within what is claimed, without departing fromthe spirit and scope of the invention.

1-13. (canceled)
 14. A method of protecting activatedmetalloaluminophosphate molecular sieve from loss of catalytic activity,comprising contacting the activated metalloaluminophosphate molecularsieve with a gas containing water at a temperature and water partialpressure effective to maintain a predetermined catalytic activity indexand stopping contact of the activated metalloaluminophosphate molecularsieve with the gas and contacting with an oxygenate to form an olefinproducts wherein the catalytic activity index is represented by theformula:CAI=exp(f(T)*f(PP _(water))^(n)*alpha*t) wherein t=time of contact ofcatalyst with water (hours) T=temperature at contact (° C.)PP_(water)=Partial Pressure of water in contact gas (psia) alpha=−0.071n=3.5 f(T)=exp(ea(1/(T+273)−1/(T_(o)+273))) ea=−5500° K T_(o)=200° C.f(PP_(water))=(26.2*PP_(water)/P_(sat)+1.14)*0.175, for T≧180° C. (453°K) f(PP_(water))=((26.2+0.272*(180−T))*PP_(water)/P_(sat)+1.14)*0.175,for 180° C. (453° K)>T≧150° C. (433° K) P_(sat)=Saturation pressure ofwater at T (psia). 15-28. (canceled)
 29. A method of protectingcatalytic activity of an activated metalloaluminophosphate molecularsieve in olefin forming reactions due to contact with water vapor,comprising contacting the activated metalloaluminophosphate molecularsieve with a gas for a time effective to maintain the activatedmetalloaluminophosphate molecular sieve at a catalytic activity index ofat least 0.7 and at an ethylene or propylene selectivity of at least 25wt % and stopping contact of the activated metalloaluminophosphatemolecular sieve with the gas and contacting with an oxygenate to form anolefin product and stopping contact of the activatedmetalloaluminophosphate molecular sieve with the gas and contacting withan oxygenate to form an olefin product, wherein the gas is at a relativewater pressure of from 0.0001 to
 1. 30. A process for forming olefinproduct from oxygenate feed, the process comprising the steps of: a)contacting an activated metalloaluminophosphate molecular sieve with agas containing water at conditions effective to maintain the activatedsieve at a catalytic activity index of at least 0.7 and an ethylene orpropylene selectivity of at least 25 wt %; and b) contacting thewater-contacted sieve with an oxygenate feed to form an olefin product,wherein the olefin product contains greater than 50 weight percentolefin, based on total weight of hydrocarbon produced.
 31. The processof claim 30, wherein the activated metalloaluminophosphate molecularsieve is contacted with the gas for a time effective to maintain acatalytic activity index of at least 0.8.
 32. The process of claim 31,wherein the activated metalloaluminophosphate molecular sieve iscontacted with the gas for a time effective to maintain a catalyticactivity index of at least 0.9.
 33. The process of claim 30, wherein thegas has a relative water pressure of at least 0.0001.
 34. The process ofclaim 33, wherein the gas has a relative water pressure of at least0.001.
 35. The process of claim 34, wherein the gas has a relative waterpressure of at least 0.01.
 36. The process of claim 35, wherein the gashas a relative water pressure of at least 0.1.
 37. The process of claim30, wherein the gas contacts the activated molecular sieve at at atemperature of from 150° C. to 300° C.
 38. The process of claim 30,wherein the activated metalloaluminophosphate molecular sieve iscontacted with the gas for not greater than 500 hours.
 39. The processof claim 38, wherein the activated metalloaluminophosphate molecularsieve is contacted with the gas from 0.01 hour to 50 hours.
 40. Theprocess of claim 30, wherein the activated metalloaluminophosphatemolecular sieve is a silicoaluminophosphate molecular sieve.
 41. Theprocess of claim 30, further comprising polymerizing olefin in theolefin product, in the presence of a polymerization catalyst system in apolymerization reactor, to produce one or more polymer products.
 42. Aprocess for converting oxygenate to an olefin product, the processcomprising the steps of: a) loading an activated metalloaluminophosphatemolecular sieve into a reaction system; b) contacting the activatedmetalloaluminophosphate molecular sieve loaded into the reaction systemwith a gas containing water at conditions effective to maintain theactivated sieve at an ethylene or propylene selectivity effective toconvert an oxygenate feed to an olefin product, wherein the olefinproduct contains greater than 50 weight percent olefin, based on totalweight of hydrocarbon produced; and c) contacting the water-contactedsieve with an oxygenate feed to form the olefin product.
 43. The processof claim 42, wherein the activated metalloaluminophosphate molecularsieve is contacted with the gas for a time effective to maintain acatalytic activity index of at least 0.7.
 44. The process of claim 43,wherein the activated metalloaluminophosphate molecular sieve iscontacted with the gas for a time effective to maintain a catalyticactivity index of at least 0.8.
 45. The process of claim 44, wherein theactivated metalloaluminophosphate molecular sieve is contacted with thegas for a time effective to maintain a catalytic activity index of atleast 0.9.
 46. The process of claim 45, wherein the gas has a relativewater pressure of at least 0.0001.
 47. The process of claim 46, whereinthe gas has a relative water pressure of at least 0.001.
 48. The processof claim 47, wherein the gas has a relative water pressure of at least0.01.
 49. The process of claim 48, wherein the gas has a relative waterpressure of at least 0.1.
 50. The process of claim 42, wherein the gascontacts the activated molecular sievc at a temperature of from 150° C.to 300° C.
 51. The process of claim 42, wherein the activatedmetalloaluminophosphate molecular sieve is contacted with the gas fornot greater than 500 hours.
 52. The process of claim 51, wherein theactivated metalloaluminophosphate molecular sieve is contacted with thegas from 0.01 hour to 50 hours.
 53. The process of claim 42, wherein theactivated metalloaluminophosphate molecular sieve is asilicoaluminophosphate molecular sieve.
 54. The process of claim 40,further comprising polymerizing olefin in the olefin product, in thepresence of a polymerization catalyst system in a polymerizationreactor, to produce one or more polymer products. 55-65. (canceled) 66.A method of activating metalloaluminophosphate molecular sieve, themethod comprising the steps of: a) providing a metalloaluminophosphatemolecular sieve containing template; b) calcining themetalloaluminophosphate molecular sieve in a calcination unit to removethe template; c) sweeping gas through the calcination unit to cool thecalcined metalloaluminophosphate molecular sieve, while maintaining thecalcined metalloaluminophosphate molecular sieve at a catalytic activityindex of at least 0.7, wherein the gas has a relative water pressure ofat least 0.0001 and contacts the activated molecular sieve at atemperature less than water critical temperature; and d) removing theactivated metalloaluminophosphate molecular sieve from the calcinationunit and contacting the removed molecular sieve with an oxygenate toform an olefin product.
 67. The method of claim 66, further comprisingpolymerizing olefin in the olefin product, in the presence of apolymerization catalyst system in a polymerization reactor, to produceone or more polymer products. 68-69. (canceled)
 70. A method ofstarting-up an olefin forming reaction system, comprising the steps of:a) sweeping gas through the reaction system to heat up the system,wherein the reaction system contains activated metalloaluminophosphatemolecular sieve and the activated metalloaluminophosphate molecularsieve is maintained at a catalytic activity index of at least 0.7 whilethe system is at a temperature less than water critical temperature; andb) contacting the activated metalloaluminophosphate molecular sieve inthe heated up system with an oxygenate to form an olefin product. 71.The method of claim 70, wherein the activated metalloaluminophosphatemolecular sieve is maintained at a catalytic activity index of at least0.8 while the system is at a temperature less than water criticaltemperature.
 72. The method of claim 71, wherein the activatedmetalloaluminophosphate molecular sieve is maintained at a catalyticactivity index of at least 0.9 while the system is at a temperature lessthan water critical temperature.
 73. The method of claim 70, wherein thegas has a relative water pressure of at least 0.0001.
 74. The method ofclaim 73, wherein the gas has a relative water pressure of at least0.001.
 75. The method of claim 74, wherein the gas has a relative waterpressure of at least 0.01.
 76. The method of claim 75, wherein the gashas a relative water pressure of at least 0.1.
 77. The method of claim70, wherein the system is at a temperature of from 150° C. to 300° C.78. The method of claim 70, wherein the activatedmetalloaluminophosphate molecular sieve is contacted with the gas fornot greater than 500 hours while the system is at a temperature lessthan critical water temperature.
 79. The method of claim 78, wherein theactivated metalloaluminophosphate molecular sieve is contacted with thegas from 0.01 hour to 50 hours while the system is at a temperature lessthan critical water temperature.
 80. The method of claim 70, wherein theactivated metalloaluminophosphate molecular sieve is asilicoaluminophosphate molecular sieve.
 81. The method of claim 70,further comprising polymerizing olefin in the olefin product, in thepresence of a polymerization catalyst system in a polymerizationreactor, to produce one or more polymer products.
 82. The method ofclaim 70, wherein the catalytic activity is catalytic activity inreaction processes selected from the group consisting of catalyticcracking, hydrocracking, dewaxing, olefin forming reactions, aromaticsforming reactions, paraffin isomerization, olefin isomerization,paraffin hydroisomerization, olefin hydroisomerization, olefinoligomerization, olefin polymerization, reforming, alkylation, anddisproportionation of aromatics.
 83. The method of claim 70, wherein theactivated molecular sieve is maintained at an ethylene or propyleneselectivity of at least 25 wt % while the system is at a temperatureless than water critical temperature.
 84. A method of shutting-down anolefin forming reaction system, comprising the steps of: a) contactingan activated metalloaluminophosphate molecular sieve in a reactionsystem with an oxygenate to form an olefin product; b) stopping contactof the activated metalloaluminophosphate molecular sieve with theoxygenate; and c) sweeping gas through the reaction system to cool downthe system, wherein the activated metalloaluminophosphate molecularsieve is maintained at a catalytic activity index of at least 0.7 whilethe system is at a temperature less than water critical temperature. 85.The method of claim 84, wherein the activated metalloaluminophosphatemolecular sieve is contacted with the gas for a time effective tomaintain a catalytic activity index of at least 0.8.
 86. The method ofclaim 85, wherein the activated metalloaluminophosphate molecular sieveis contacted with the gas for a time effective to maintain a catalyticactivity index of at least 0.9.
 87. The method of claim 84, wherein thegas has a relative water pressure of at least 0.0001.
 88. The method ofclaim 87, wherein the gas has a relative water pressure of at least0.001.
 89. The method of claim 88, wherein the gas has a relative waterpressure of at least 0.01.
 90. The method of claim 89, wherein the gashas a relative water pressure of at least 0.1.
 91. The method of claim84, wherein the system is at a temperature of from 150° C. to 300° C.92. The method of claim 84, wherein the activatedmetalloaluminophosphate molecular sieve is contacted with the gas fornot greater than 500 hours while the system is at a temperature lessthan critical water temperature.
 93. The method of claim 92, wherein theactivated metalloaluminophosphate molecular sieve is contacted with thegas from 0.01 hour to 50 hours while the system is at a temperature lessthan critical water temperature.
 94. The method of claim 84, wherein theactivated metalloaluminophosphate molecular sieve is asilicoaluminophosphate molecular sieve.
 95. The method of claim 84,wherein the catalytic activity is catalytic activity in reactionprocesses selected from the group consisting of catalytic cracking,hydrocracking, dewaxing, olefin forming reactions, aromatics formingreactions, paraffin isomerization, olefin isomerization, paraffinhydroisomerization, olefin hydroisomerization, olefin oligomerization,olefin polymerization, reforming, alkylation, and disproportionation ofaromatics.
 96. The method of claim 84, wherein the activated molecularsieve is further maintained at an ethylene or propylene selectivity ofat least 25 wt %. 97-105. (canceled)
 106. A method of starting-up anolefin forming reaction system, comprising the steps of: a) sweeping gasthrough the reaction system to heat up the system, with the reactionsystem containing activated metalloaluminophosphate molecular sieve,wherein the activated molecular sieve is maintained at a temperatureabove water critical temperature; and b) conacting the activatedmetalloaluminophosphate molecular sieve in the heated up system with anoxygenate to form an olefin product.
 107. A method of shutting-down anolefin forming reaction system, comprising the steps of: (a) contactingan activated metalloaluminophosphate molecular sieve in a reactionsystem with an oxygenate to form an olefin product; (b) stopping contactof the activated metalloaluminophosphate molecular sieve with theoxygenate; (c) sweeping a gas through the reaction system to cool downthe system, while the the activated metalloaluminophosphate molecularsieve is maintained at a temperature above water critical temperature.